The Reason You’re Not Losing Weight

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Original article by Lyle McDonald, if you don’t follow his work already, you should.

Although I have other pieces ready, I wanted to follow up my Dumb Shit Fitness Professionals Say #1. And I wanted to do that by showing what being helpful is. To whit, I’ve redone that stupid “Eating like an Asshole” thing to be correct and useful rather than a piece of trash. So now let me show you the real reasons you’re not losing weight.

Here it is, probably the closest to an Infographic I’ll ever make.

Real Reasons You're Not Losing Weight

Click it to make it bigger for saving. There’s a full size version at the end of the article.

Now let me examine the real reasons you’re not losing weight.

Reasons You’re Not Losing Weight: Myths

First let me look at some of the common myths to explain why you’re not losing weight. This can’t even begin to be comprehensive so I’ve just chosen some of the more representative ones.


The idea that insulin was the cause of obesity or could prevent weight loss can be traced to Gary Taubes. Who, after 5 years of “dedicated research” drew a stupid conclusion that people still believe to this day. That conclusion being that insulin levels, rather than calorie intake caused obesity. Tim Noakes, who used to be a forward thinking physiologist, is a more recent convert to the cult. Which is simply sad.

The idea here is that high insulin causes obesity and/or just lowering insulin will cause fat loss/prevent obesity. Therefore, goes the logic, just stop eating carbohydrates to lower insulin and obesity is solved. The idea isn’t even new, only the nonsensical rationale.

And it’s wrong. Modulating insulin levels from the low to high range just doesn’t impact on much. There is also the fact that protein raises insulin just fine and we know it doesn’t cause weight gain. And factually fat can store itself without raising insulin at all. The whole idea is crap.

Related: What Is the Glycemic Index?

Meticulous work by Kevin Hall has shown the insulin hypothesis to be garbage. Quite in fact, at least one of his studies was funded by a low carb group called NuSi. It still found a negative result which must have been a real kick in the nuts.

Not that it matters. Taubes has stated that “No evidence will change my mind.” That’s not science. That’s gurudom. Because research apparently only mattered until he had his first book deal. And then nothing would change his mind.

Which isn’t to say that for people with insulin resistance, lowered carbohydrate diets may not be better in many ways. But there’s no magic effect on body weight outside of any impact on food intake.

Eating Carbohydrates

This is just an extension of the previous topic. Since carbohydrates raise insulin, so the logic goes, eating carbohydrates either causes weight gain or prevents weight loss. And it’s untrue. In a calorie controlled situation, high and low-carbohydrate diets cause about the same weight loss.

Some will point out that bodyweight drops rapidly when carbohydrates are removed from the diet. And that it goes up similarly when they are reintroduced. But this is just water going on and off of the body. It doesn’t mean anything.

Related: What Are Carbohydrates?

Eating Sugar

An extension of the previous topic, people who will eat carbohydrates in their diet think of sugar as the devil. There are various arguments here but they usually go back to insulin. Which is funny because the insulin response to sugar is lower than to many “good” carbohydrates. It’s glycemic index is lower than potatoes.

And there is nothing inherently evil about sugar in this regard. Quite in fact, years ago I stated that if someone got sufficient protein, they could eat nothing but table sugar and lose fat. Imagine the response.

Except that people have done this. So we had one guy do The Twinkie Diet and another who did the Ice Cream Diet. And they both worked fine in terms of causing weight loss. Am I saying to do this? No, of course not. It simply makes the point: sugar intake does not explain why you’re not losing weight.

Sugar cannot magically prevent weight loss. Quite in fact, when calories are controlled, replacing some complex carbs with sugar has no impact on weight loss.

Eating Some Specific Food

Just another extension of the above. Sometimes rather than broad categories of foods, people think a specific food is why they’re not losing weight. Usually it’s their own pet trouble food. Or one that they stopped eating at some point and finally lost weight. Aha, they conclude, that food stops weight loss. Except that what happened was that not eating that food made them eat less.

Gluten is a common one here and I’m sure there are a lot of these if you take the time to look. Dairy is one that gets trotted out a lot in various circles. What’s hilarious about this one is that study after study shows that dairy improves fat loss on a diet. Not only is the myth untrue, it’s completely backwards.

Not Clean Eating/Doing a Specific Magic Diet

A further extension of the above is the idea that if you’re not following some specific magic diet, you will be prevented from losing weight. Here, the perfect diet is the one that whomever you’re talking to is on.

Take your pick: clean eating, Paleo, carnivore, IF, IIFYM (not really a diet), etc. Whatever worked for them is the right diet. If you’re not losing weight, you just need to switch to their magic diet. I mean, it worked for them!

The simple fact is that this can’t be true. On any diet you name, some do great, some are ok and some fail. If there were a single correct magic diet we’d know what it is. I mean, we do: it has to have sufficient protein and create a deficit.

Beyond that, the difference in results between diets is minimal. What mostly matters is that people can adhere to it in the long term. And I was saying that over 15 years ago.

Starvation Mode

Ok, starvation mode. This one has been around for decades. The basic idea being that if you do certain things the body will go into this mode and “hoard calories and store fat.” Various ideas tend to follow from this.

One is that if you miss breakfast, your body will go into fat storing mode. This idea came out of animal research and it’s nonsense. For an animal missing a single meal is a huge deal. For humans it’s irrelevant. Also, the Intermittent Fasting data shows it’s untrue.

A similar idea is that if you don’t eat every 3 hours you go into starvation mode. Same thing, came out of animal research. In humans, meal frequency has no measurable impact on energy expenditure.

What’s even funnier about this one is that it’s actually reversed. In humans, fasting completely for 3-4 days actually RAISES metabolic rate.

Metabolic Damage

And then there is the idea of metabolic damage, that you can do permanent damage to your metabolism through extreme dieting. It’s been around for years in one form or another with entire books about “fixing it” out there.

Related: Is Metabolic Damage Real?

At a conceptual level, to explain starvation mode or metabolic damage, you’d have to explain how people living in food ravaged countries are all emaciated. Didn’t their bodies go into starvation mode? No, because it’s not a thing.

Which isn’t to say that there aren’t endless metabolic adaptations to fat loss. Energy expenditure absolutely goes down, appetite goes up and there’s more. But that’s not damage. And it’s not storage mode. And none of the adaptations can cause someone to GAIN FAT if they are in a deficit.

Slow Metabolism

The idea of a slow metabolism causing someone to gain weight or as an explanation for why you’re not losing weight is decades old. It still gets thrown around as an explanation. And, well, it’s not true.

Outside of some rather severe disease states, the idea of a low metabolic rate just isn’t a thing. Invariably when someone online claims such and goes and gets their metabolic rate measured, it’s stock normal.

Related: What Determines How Many Calories I Burn in a Day?

Quite in fact, as people’s bodyweight (well lean body mass) goes up, so does their resting metabolic rate. It’s simple, to a point, bigger people burn more calories.

LBM Metabolic Rate Relationship

Certainly there is variability at any given bodyweight as you can see in the graph. For any given weight there may be relativly higher or lower values. LBM only explains a majority of BMR, not all of it. Even here variations in BMR don’t predict weight gain.

Which isn’t to say that total daily energy expenditure may not be lower in overweight individuals due to lower activity levels. But this is not a “slow metabolism” so much as low activity. Usually the issue is in Non-Exercise Activity Thermogenesis with NEAT being low.

Related: What is Non-Exercise Activity Thermogenesis?

There are a couple of reasons for this. One is that heavier individuals often don’t move around much. No, I’m not playing the “gluttony card”. It’s just physics. But part of it is that there is a biological driver on activity levels, it lives in the dopamine system. And it’s just as likely that a deficit here predisposes individuals to move less, allowing them to gain weight.

But by and large there is no such thing as a slow metabolism.

Low Thyroid

Which brings me to the idea of people having low thyroid hormone levels. This one must date back to the 50’s or 60’s when nobody knew nothin’ about nothin’. I think they sort of assumed that low thyroid caused obesity and they handed out thyroid drugs like candy. Which caused all kinds of fun tachycardia and muscle loss.

Funfact: DNP is safer than thyroid medications.

Which isn’t to say that some people aren’t truly hypothyroidal in a clinical sense. That still can’t stop weight loss although it makes it harder. Energy expenditure is down and water retention is common which can mask weight loss. But people with true hypothyroidism have lots of other symptoms. Factually, in most cases this is not an explanation.

Endless Other Myths

And that is seriously just touching the surface of the topic. People repeat the endless myths and they refuse to die. So of course people are confused.

Especially when lazy ass “Fitness Professionals” tell them to “Do their own research” rather than pointing them to better information. Because they’d rather be judgmental and call them an asshole for not knowing what they can’t know.

Reasons You’re not Losing Weight: Realities

With some of the common myths covered, let’s move to the realities of the topic. Some actual reasons you’re not losing weight. Again, I can’t be comprehensive and will only hit on the big ones.

Underestimating Your Food Intake

In all honesty, this is usually the explanation for why people can’t lose weight. Simply, they are eating more than they think. Research shows that people may underestimate their food intake by 20-50% at least. That is, what they think they are eating is 20-50% less than what they are actually eating.

Literally everybody misreports their food intake. Lean people, overweight people, active people, inactive people are all terrible at estimating their food intake. Even registered dieticians are bad at it.

Among other things, this is why epidemiology is crap. The food reports are garbage. Because everybody sucks at this.

Related: Is Self-Reported Food Intake Accurate?

And in a weight loss context, this means that people who think they are only eating 1200 calories may be eating 1800. And that’s why they can’t lose weight. There are all kinds of TV shows where they find someone who says they have a broken, slow metabolism. Who say they don’t eat very much. And they add up the daily food and it’s like 8,000 calories or more. People are terrible at his.

The modern world has simply broken our concept of portions and calorie amounts. They will do these on the street things and ask people how many calories in a large pizza. People will say 400 when it’s more like 4000.

And, going back to metabolic damage, THIS is why those people reporting gaining fat on low calories were doing nothing of the sort. They were simply underreporting their food intake. And we told Layne this. And he went to the guru well of ad hominems and bullshit to avoid the truth.

Hilariously Layne is now sharing stuff on Instagram about how you’re not losing weight because you’re underreporting your food intake. But when metabolic damage seminars were on the line, science didn’t matter. It only matters now so he can pretend he didn’t sell people lies for 5 years to buy a mansion (and afford moving to Australia). Isn’t that right?

Overestimating Your Calorie Expenditure

Coming right out of the above is the fact that most people overestimate how many calories they are burning through exercise. And that overestimation is in the same realm as the calorie underestimation if not worse.  In one study, lean women and men though they were burning 3-4 times as many calories as they actually were.  Think about this, they thought a 300 calorie exercise bout burned 900-1200 calories.

And a lot of this is due to people being told that this is the case.   You’ve got all these exercise programs telling people “You’ll burn 900 calories per hour.”  Or reading that they’ll burn 1000 calories in a 45 minute exercise class.  And in reality it’s more like 450 for a larger man and 300 for a smaller woman.

Yes, a trained endurance athlete can burn 15 cal/minute but they’re working. That’s 900 calories an hour. Most people are lucky to get 10 cal/minute and many will burn less.  That’s, at best, 600 calories per hour.  And weight training factually burns jack shit for calories. A solid hour of training might be 400-450 for a larger male and 250-350 for a smaller female. Gardening burns more.

And when you combine underestimated calories with overestimated activity levels, it’s a double whammy. You think you’re eating 1200 calories and you’re eating 1800. You think you’re burning 900 calories in exercise and you’re burning 450. And that deficit that should exist is now a surplus.

Your Diet is Too Restrictive and You End up Bingeing

Another common problem is, in general terms, not adhering to the diet. In fact, this can explain many weight loss stalls outright. But it can go further when people are trying to follow super extreme diets and end up losing control and bingeing more often than not.

So, assuming their food intake is what they think it is, they shoot for 800 calories per day.  They actually achieve that before blowing up and eating 2500 calories one day.  At which point they go back to trying to restrict calories as hard as possible, which leads to another binge.  And over the full week they end up being at about a net zero result.

Note: I am well aware of approaches like ADF and ICR and calorie cycling for athletes.  I’ve only been writing about them for 2 decades  That’s not what I’m talking about here and you know it.

And when you ask this person their calorie intake, they don’t want to talk about the binges. So they say they are eating 800 calories (really 1200) and are not losing weight. But you don’t hear about the 2500+ calorie days.  Which then leads you to conclude that they must be metabolically damaged or something.

Note: Yes, I have a Rapid Fat Loss diet based around very low calories. It’s different for specific uses. And research actually shows that rapid initial fat loss is better in the long-term. But it’s usually best for short periods of time.

The Rapid Fat Loss Handbook: A Scientific Approach to Crash Dieting

In any case for many people targeting a higher calorie level is better in the long term.  So they target 1400 calories per day or whatever and actually stick to it rather than bouncing low and high.

Your Rigid Eating Attitudes are Doing More Harm Than Good

This ties into the previous topic and the idea of rigid and flexible dieting (I prefer flexible eating).  Rigid dieting attitudes refer to conceptualizing food as good/bad or thinking in black and white.   In contrast, flexible eaters recognize shades of gray.

And study after study after study shows that flexible eating attitudes are superior to rigid ones overall.  Certainly, some get away with rigid eating approaches, usually athletes with an extreme goal. But for most it fails.  You can see this in droves in the clean eating community.  For every one person who makes it work, you can find dozens who fly off the rails.  They binge constantly, suffer enormous mental stress. Many end up with eating disorders.

Related: What is Flexible Dieting?

Adopting more flexible eating attitudes, even if you don’t use the flexible strategies, is a key to long term success.

You Are Offsetting a Week’s Dieting on the Weekends

This is one I do see a lot of fitness professionals bring up fairly frequently.   Usually by folks who would never share the “You’re eating like an asshole” tragedy to begin with.  But this is a very real issue and problem.

Although it’s changing in the modern world, we have traditionally had a Monday through Friday work week and weekends off.  And what happens to dieters is that they are strict about their diet during the week but let things go on the weekend.

Their daily structure is changed, they have family or personal obligations, most social events revolve around food.  And it’s easy to undo a week of proper dieting (assuming you’re not underreporting your food) with a weekend of overindulgence.

Short-Term Water Retention

I’ve been writing about the issue of water retention “masking” weight and fat loss for longer than I can remember.  It’s one of those things that can happen on a diet where various mechanisms may be involved.  I’ve typically focused on cortisol here.

Cortisol is a stress hormone that can impact on water retention (Cushing’s disease is an extreme version).  And when you combine mentally stressed dieters with hard dieting and exercise you often get chronic elevations in cortisol.  And with that can come water retention.

The practical impact of this being that true weight and fat loss may be “masked” by water retention.  If someone is losing one pound per week of fat but holding 3-4 pounds of water weight due to cortisol, they may not see measurable fat loss for a month.

I’d mention that despite arguments that this is “only a theory”, starvation water retention has been known about for decades. As they stated in the excellent book The Great Starvation Experiment.

Henry, along with many others, saw his weight loss begin to plateau around the 20th week of starvation. Unlike Willoughby and Plaugher, their stalled weight losses were entirely explicable and did not put them under suspicion of cheating. Henry and the other men were suffering from edema. The condition was, as Keys would put it, one of the chief “stigmata” of starvation.

Edema was a puffy swelling caused by retained water in the body. It occurred chiefly in the ankles and knees but also in the face. Every morning, each subject found the side of his face that he had slept on swollen. Henry had a severe case. His legs were like elephant feet, virtually the same diameter all the way down from the knees to his toes.

It became uncomfortable and then impossible for him to cram his feet into his normal shoes. When he pressed a fingertip against his shins, the indentation stayed, as if he had pressed his finger into clay. He would at times amuse himself by making a row of indentations run up his leg like buttons on a shirt.

It’s a very real thing.  Just like metabolic damage was very much NOT a real thing.

Menstrual Cycle Variations in Weight (Women Only)

In addition to the normal diet related water retention that can occur, women have to deal with the menstrual cycle. While it varies between women, bodyweight can swing up and down week to week.  For women, trying to compare weight every week is a non-starter.  Instead, they have to compare Week 1 of the cycle to Week 1 of the next cycle.

The Menstrual Cycle

This phenomenon can make it look like a woman isn’t losing weight.  But it’s simply water shifts across the month masking actual progress.  It goes without saying, but I’ll say it anyway, that I discuss this in detail in The Women’s Book Volume 1.

Other Actual Reasons

And that’s just a sampling of the actual research and reality based reasons you’re not losing weight.  Like with the myths, there are others but the above tend to be the big ones in my experience.

And they are the ones that fitness “professionals” should be educating you about rather than calling you an asshole for not knowing what you don’t know.  Because as professionals, or even active people who want to see people be healthy, you should either be helpful or shut the fuck up.

This is your obsession, or your career.  Rather than being a judgemental prick because someone has been misled by endless bullshit, EDUCATE them.   Start by showing them my graphic.

So Here’s My Graphic

So here’s the full size version of the graphic I put together.  Please feel free to download it and share it.  It will hopefully do a fuckload more good than the one calling people an asshole for not knowing what they can’t possible know.

Do note, it has my logo on it.  And it is COPYRIGHTED. 

You can download it, share it, etc.  But if you do, leave my logo and name on it.  I will know.

Real Reasons You're Not Losing Weight

10 Inconvenient truths about fat loss

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Fat loss can be frustrating at times. You lose fat more slowly than you think you should, your progress stalls completely, it feels like your metabolism is broken, you do cardio but it doesn’t help, or life gets in the way.

Some things that interfere with your fat loss efforts are out of your control. But in many cases, the frustration is self-inflicted because you don’t yet understand or are not yet willing to admit the truth about how fat loss – and human bodies – work.

Sometimes the facts are unpleasant. There are truths you may not want to hear, but they’re things you need to hear. As Carl Sagan once said, “Better the hard truth than a comforting fantasy.” When you learn the truth about fat loss, and accept it, you still might not be happy about it, but it’s only then that real change starts to happen.

In this in-depth Burn the Fat Blog post (about 15 minutes read time), you’ll learn 10 of the most inconvenient fat loss truths, that if you understand, accept, and respond to the right way, you will break through any past barriers and forge on to the lean body you want.

1. Too much healthy food can lead to weight gain

Fat loss happens when you achieve a calorie deficit. Yet not all diets ask you to count calories. Some diets are based on the premise that all you have to do to lose weight is to eat certain foods – namely the unprocessed, nutrient-dense foods, and avoid others – the processed, nutrient-sparse foods.

Guidelines urging you to eat unprocessed foods are well-intentioned on two levels. One is because less processed foods make you healthier. The other is because processed foods are usually more calorie-dense and hyper-palatable, so focusing on eating healthier foods usually does help you control calories, and that helps with fat loss.

But there are always many frustrated dieters screaming, “I’m eating healthy, but not losing any weight!” Why does this happen?  Because you’re eating too much healthy food!

Healthy foods are not calorie-free. Too much of anything, even healthy foods, will get stored as fat. You don’t get an unlimited all you can eat pass. Ever. But for some reason this fact does not register in the brains of many health food eaters.

Many foods with a reputation for being healthy, especially fats like avocado, natural peanut butter and olive oil, are incredibly calorie dense and easily overeaten into surplus levels. Making it worse, the popularity of keto diets has normalized eating more fat, including things like coconut oil, which is perceived by some people as healthy but adds hundreds of extra calories to their diets.

The truth is, eating healthy foods doesn’t get you lean. Eating healthy foods gets you healthy. A sustained calorie deficit gets you lean.

2. You can lose weight and stay lean on a junk food diet

Admit it. It drives you insane when you see a friend or family member “eat anything they want” and still stay slim. These are not mythological creatures – you will meet people that you personally witness eating cookies, ice cream, chocolate, pizza, and just about anything else they like, and they don’t carry an ounce of excess body fat, nor seem to gain any. It doesn’t seem fair.

Your knee jerk reaction is to assume they’re genetically gifted with a fast metabolism. What you don’t see or add up is how their total calorie intake for the whole day and whole week equals their maintenance level. That’s why they don’t gain weight. It’s not their metabolism, it’s math. If you’re not in a surplus, you don’t gain weight.

Proof of this concept can be found in the numerous diet experiments like the one Mark Haub did. Remember him? He’s the Kansas State professor who made headlines by losing weight on a Twinkie diet. How? He tracked his calories and made sure he had a deficit. Stunts like this have been documented by people who ate nothing but McDonalds as well. Twinkies don’t turn into fat. McDonalds doesn’t turn into fat. Excess calories turn to fat.

Do I recommend eating a lot of junk and fast food in a deficit because you can get away with doing that and still lose weight? Of course not. We aim to eat healthy unprocessed foods 80 or 90 percent of the time so we can be lean and healthy, not just lean. While health and fat loss overlap, they are two separate goals. If you want to achieve both, then you’d better get calorie quantity and calorie quality right, not one or the other.

3. You don’t have a slow metabolism

Yes, your metabolism slows down after dieting and losing weight. The technical name is adaptive thermogenesis, or simply metabolic adaptation. This is the normal response that everyone has to dieting and weight loss.

Is it enough to slow down progress slightly and frustrate you because your rate of fat loss doesn’t match what you’d predict on paper? Yes. Does it stop or prevent weight loss? No. Metabolic adaptation is a real thing, but having a slow metabolism does not hold up as a reason for not losing weight.

A study done at St Luke’s-Roosevelt Hospital in New York was especially enlightening because it involved subjects who reported a history of “diet resistance.” They claimed they ate only 1200 calories per day but weren’t losing weight. They’d been stuck at the same weight for at least six months. They blamed their lack of results on slow metabolism, genetics, or thyroid problems.

First, before sharing what this study found, let’s clear something up: The belief that obese people have a slower metabolism is a myth. In fact, the opposite is true. Men and women with a large body mass burn more calories because resting metabolic rate is directly linked to total body mass.

Big heavy people burn more calories than smaller lighter people. This is why obese people can lose so much more weight each week than smaller people – it’s much easier to create a huge calorie deficit. Plus, the calorie cost of moving around a large body is greater than moving a light body.

Even with this in mind, many overweight people assume they’re unique and really are cursed with a genetically inherited slow metabolism.

So now, back to this classic study, which was published in the New England Journal of Medicine (NEJM). The researchers wanted to settle the issue by doing an experiment where calories eaten and calories burned were measured under tightly controlled conditions.

The subjects were given a test for resting metabolic rate, the thermic effect of food, and the thermic response to exercise. They also used doubly labeled water (an accurate method to measure energy expenditure under free-living conditions). Body composition was tested with underwater weighing.

The results were a surprise to the subjects, but confirmed the hypothesis of the researchers:

The resting metabolic rate, the thermic effect of food, oxygen consumption in response to exercise and total energy expenditure did not differ significantly between the test groups. None of these subjects who swore up and down they were “diet resistant” had a low resting metabolic rate or a low total energy expenditure.

Why weren’t they losing weight? That’s the next inconvenient truth.

4. You eat more calories than you think

Almost everyone eats more than they think. Why? Because almost all of us are bad at estimating how many calories are in our food. It’s not easy to eyeball a food portion and correctly guess the calories (darn near impossible in restaurants).

Granted, it’s possible for some people to manage food portions and control their weight if they master intuitive eating and mindfulness skills. But when nothing else is working, the only sure-fire solution to underestimating calorie intake is to weigh and measure food and track the calories and macros.

In the same NEJM study which found that so-called “diet resistant” people did not have slow metabolisms, they also discovered the real cause for the lack of weight loss: The subjects underestimated their calorie intake by 47%! That’s not a minor mistake – that’s a massive “make you or break you” kind of mistake!

The researchers said, “The failure of some obese subjects to lose weight while eating a diet they report as low in calories is due to an energy intake substantially higher than reported, not to an abnormality in thermogenesis.”

To be fair, we should acknowledge that there are some clinical explanations for short term diet resistance. For example, undiagnosed and untreated thyroid disease could cause difficulty with losing weight. Certain medications can stimulate appetite or decrease calorie burning. And there are a handful of medical conditions that can hinder fat loss efforts

In this study however, people with these issues were excluded, so these exceptions were ruled out. Lack of weight loss wasn’t caused by slow metabolism, thyroid problems, or medication, it was caused by eating too much food.

It’s important to know that we’re not saying frustrated dieters are dishonest about how much they eat. They’re simply not aware that they eat so much because it’s so hard to guess the calories in meals, and so easy to lose track over time.

5. You think you burn more calories than you do

Equally alarming as the underestimation of calories eaten is the overestimation of calories burned. In the NEJM study, the subjects not only under-estimated their food intake by 47%, they over-estimated how many calories they burned by 51%! Think for a minute about the impact of both put together.

In a different study, researchers from York University in Toronto had a group of test subjects exercise on a treadmill for 25 minutes at either a moderate or intense level. After the exercise, they were asked to estimate the number of calories they burned and create a meal containing that many calories.

This study was also cleverly designed in the way they used different groups, including some individuals who were not trying to lose weight. There were four types of participants in the study:

1. Normal weight
2. Overweight
3. Trying to lose weight
4. Not trying to lose weight

Every subject did a poor job trying to estimate calories burned, with one group (overweight, not trying to lose weight), doing a terrible job: They overestimated their calories burned by 72%!

The subjects who were trying to lose weight did better, but still failed to accurately estimate their calories burned and eaten. In all the participants from all four groups, there was a range of calories burned estimation error between 280 and 702 calories per day.

6. You probably eat back some or all of the calories you burn

“Exercise is not effective for weight loss.”
“Cardio is a waste of time.”
“Aerobics makes you fat.”
“Some people are cardio-resistant.”
“You adapt to cardio so eventually it stops working.”

What do these five statements, each one made by prominent diet book authors or personal trainers, have in common? Aside from the fact that they’re wrong, they’re all alike because they miss or ignore the real reason why cardio doesn’t increase fat loss (“doesn’t work”) for some people…

But first, why would people say these things? Well, it’s not my intention to belittle anyone for saying that exercise doesn’t seem to help them lose weight. In fact, studies have confirmed that a fixed amount of aerobic exercise doesn’t produce the same amount of weight loss in different individuals.

The problem is in the way some people try to explain the reason they’re not losing weight.

It’s not because exercise doesn’t work for fat loss (it does, and reliably so).
It’s not because calories don’t count (they do).
It’s not because they are exercise-resistant (they’re not).

The biggest reason different people get different results from the same cardio is because they all may do the exercise consistently, but diet compliance varies from person to person.

Many people start doing cardio or increase their cardio, but at the same time, usually unconsciously, they fail to stay on their diet plan. They exercise more, but also eat more, which cancels out the fat loss benefit of the exercise (increasing a deficit). Researchers call these people “compensators.”

Some experts claim that people eat more because cardio increases their appetite. This may happen in some people with some types of cardio, but exercise does not always increase appetite – that’s a myth. In some cases, it even suppresses appetite.

Even if your appetite does go up after doing cardio, if you eat more in response to that, it doesn’t mean the exercise doesn’t work, it means you made a diet mistake (compensation). Contrary to popular wisdom from intuitive eating, if your goal is fat loss, you should not always eat when you’re hungry. Harsh truth: You have a deficit you must comply with, and sometimes you have to feel hungry and not eat.

This mistake is also common because it’s a mental response as much as physical. In psychology there’s a concept known as moral licensing. It means there’s a human tendency for doing something good for yourself, then seeing that as permission to do something bad. Exercising and then rewarding yourself with junk food is the classic example.

Many people also go through a conscious rationalization process where they figure if they exercised, they “earned” more food and can get away with eating more because they worked out. This problem is compounded because of how most people think they burn more calories than they do.

Even worse, people who use fitness trackers to monitor how many calories they burn and then adjust their food intake based on calories burned are often unknowingly sabotaging themselves.

7. Deciding how much to eat based on how many calories a fitness tracker says you burned can make you fatter

Tracking the calories you burn from your workouts could sabotage your fat loss? What? Aren’t you supposed to do that? Isn’t it a good idea to use fitness trackers to monitor your calorie burn? Don’t you want to know how many calories your 45 minutes on the treadmill burned off?

Obviously, it matters how many calories you burn each day – that’s part of the energy balance equation. Being more active is great for fat loss and fat loss maintenance.

But if you try to use information about calories burned from each workout to make adjustments to how much you eat each day, you’re in grave danger of making a monumental fat loss mistake.

Most people want to know how many calories each workout burns because they think they can reconcile calories in versus calories out, adjust their food intake up or down, and try to ensure a calorie deficit every day.

Most people also figure if they burn more on one day, they’ll eat more, and if they burn less on another day they’ll eat less. Often, they rationalize that if an epic workout burns a lot more than usual, they have plenty of room to add in a treat meal or an extra tasty snack.

This all seems perfectly logical, and in some ways, it is. If you burn 3000 calories a day, you can eat a lot more than someone who only burns 2000 calories per day and still lose weight.

Yet most people are surprised or shocked when I tell them you don’t need to know how many calories each individual workout or activity burns.

Here’s why: Your exercise calories burned were already counted.

When you initially set up your nutrition plan, the first thing you do is use a calorie calculator formula to estimate your basal metabolic rate (BMR). That’s how many calories you burn just to cover basic body functions.

The second thing you do is estimate your activity level. This includes formal workouts as well as work, walking and all other daily activity. This is where your average daily exercise calories burned are already counted, in advance.

When you multiply your BMR by your activity factor, you then have your total daily energy expenditure (TDEE) also known as your maintenance level. That’s the grand total of all the calories you burn in a day.

You can do these calculations by using equations such as the Katch-McArdle or the Harris-Benedict calorie formula.

If you want to lose fat, the third step for meal plan set up is you simply drop calories a little below that, maybe 20 to 30% under maintenance. That deficit is where your weight loss comes from.

Here’s the key point: Since you already counted all your exercise calories burned in those initial calculations, counting workout calories again would be not only be redundant, if you ate more, you’d be eating away your deficit.

Suppose you look at the treadmill readout and it says you burned 500 calories. It’s tempting, almost a natural reaction, to think you should add that on top of your daily burn and eat 500 more calories. That’s not how you manage calories for fat loss – that’s a diet mistake that wipes out your calorie deficit.

In fact, how many calories individual workouts burn should not even be your main focus. Instead, focus on the number of calories you’re supposed to eat, which you calculated in advance. Follow your baseline meal plan all week long.

Measure your results every week (weight, body composition, measurements, visual assessment) and if you achieved the fat loss you wanted, don’t change a thing. If your fat loss stalled, then decrease your calories for the next week. Alternately, increase your cardio duration or frequency or intensity.

I love fitbits and fitness trackers as a motivational tool to remind you to move more, or to record your running stats and so on. But I never recommend using a tracker for adjusting your food intake day to day.

Eating back calories burned = diet sabotage

8. One weekend of overeating can cancel out a whole week of dieting and training

Most people believe the cliché, “You can’t out-train a lousy diet” is more or less true. At the Washington University School of Medicine in St. Louis, a study was designed to find out whether a “lousy diet” on weekends specifically, was causing weight loss failure.

Prior to this study, the best evidence for weekend eating causing fat loss plateaus or weight gain, came from the National Weight control Registry (NWCR). NWCR research had found an association between lower weekday to weekend diet consistency with weight loss relapse. People who maintained the same eating patterns on weekends as weekdays were more likely to maintain their weight during the subsequent year.

The newer study was a randomized controlled trial with a large sample size, and it ran for a whole year. It measured compliance to diet and exercise during the week as compared to the weekend, as well as changes in body weight during the week as compared to the weekend.

Over the entire 52 weeks, what they discovered was that both test groups – a calorie restricted group and an exercise group – successfully adhered to their calorie deficit on the weekdays. On the weekends, however, calorie restricted participants stopped losing weight and exercise participants actually gained weight.

The study was the first controlled trial to confirm what the NWCR had reported observationally and what we always suspected: weight gain does happen on the weekends more than the weekdays and it’s because of increased calorie intake on the weekends. Things go awry because most people have different eating schedules, patterns or habits on the weekends than on weekdays.

Calorie intake was highest on Saturdays – about 236 calories more than on weekdays, mostly from fatty foods. A couple hundred calories more on Saturday doesn’t seem like much, and of course it’s possible to eat more on some days than others and still have a weekly deficit.

But the excess calories most people eat on weekends are not a part of deliberate, controlled refeeds, built into a weekly plan to maintain an overall deficit. The weekend excess most people eat is overlooked and adds up over time.

Just this barely noticeable increase in weekend food intake could cause a weight gain of nearly 9 pounds if you didn’t catch it and let it go on unchecked all year long. And of course, some people indulge even more than others from Friday night through Sunday, so the fat gain could be even higher.

There’s been a lot of research done on how diet and activity changes during the holidays and over the changing seasons. But there’s a big difference between holiday indulgence and weekend indulgence. A big splurge on your birthday, Thanksgiving, and Christmas? Okay, that’s only a few times a year. Weekends come around 52 times a year.

9. Women can’t eat like men – if they try, they won’t lose fat

Many women think they have trouble with fat loss because of hormones. But the biggest obstacle is not hormonal, it’s one little relativity factor that almost all women overlook: Women are usually smaller and lighter than men, yet their mistake is setting their calorie intake, their goals, and expectations like men (or larger women).

When you have a smaller body, you need fewer calories. When you have lower calorie needs, your relative deficit (20%, 30% etc) gives you a smaller absolute deficit. Therefore, you lose fat more slowly than someone larger who can create a bigger deficit more easily.

Me: I’m male, 5’ 8”, 192 pounds in “off-season” condition, and very active:

Daily maintenance level: 3300 calories a day
20% deficit: 660 calories
Optimal intake for fat loss: 2640 calories a day
On paper predicted fat loss: 1.3 lbs of weight loss per week

At 2640 calories per day, I’d drop fat rather painlessly. If I bumped up my calorie burn or decreased my intake by another 340 a day, that would be enough to give me 2 pounds per week of weight loss. Either way, that’s hardly starvation.

For women, especially lighter, shorter women, the math equation is very different.

At age 40 and only 5 feet tall and 115 pounds, a woman’s numbers would look like this:

Daily maintenance level: 1930 calories (even when moderately active).
20% deficit: 386 calories
Optimal intake for fat loss: 1544 calories a day
On paper predicted fat loss: only 8/10th of a pound of fat loss/week.

If you took a more aggressive calorie deficit of 30%, that’s a 579-calorie deficit which would now drop the calorie intake to 1351 calories/day.

That’s pretty low in calories, but it’s still fairly small calorie deficit. In fact, I would get to eat twice as many calories (2600 vs 1300 per day) and I’d still get almost twice the weekly rate of fat loss!

I know it’s not fair, but it doesn’t mean women can’t get as lean as they want to be. It means that on average, women will drop fat a lot slower than men. It also means petite women with small bodies will always lose fat very slowly.

The only answer is patience and meticulous tracking, because even small calorie errors turn into big setbacks. One extra muffin, cookie or serving of peanut butter, and POOF, just like that, the calorie deficit is gone.

10. You can’t burn much body fat in a 4-minute workout no matter how intense it is.

A claim that lots of people take at face value without thinking it through is that you can burn more fat with a 4-minute workout than you can with a long steady state workout, say 40 minutes, if the 4-minute workout is super high in intensity.

The mistake is confusing pounds of fat tissue being burned off your body week by week with calories burned per minute in a single workout.

Suppose you did a high-intensity workout with a huge calorie burn of around 20 calories per minute. That would mean you burned 80 calories in 4 minutes. Is that a lot of calories burned in 4 minutes? Absolutely! Are there cardio health benefits gained in only 4 minutes with an intense effort? For sure. Is it enough total calories burned to produce much body fat loss? No way.

The 4-minute workout craze came from the Tabata protocol, which is a type of HIIT where you do 20 second bursts of intense work followed by 10 seconds of rest (30 seconds per round) and you repeat that 8 times (a total of 4 minutes). It’s a legitimate training protocol and a time-efficient way to achieve fitness. But sorry, one round of that won’t put a dent in your body fat stores. Even two or three rounds – that’s better, but still, don’t expect much fat loss.

When you get up to 20 to 30 minute high-intensity interval workouts, or 40 to 45 minute moderate intensity steady cardio, then you’ll start to see the body fat fall off you. (If you don’t mess up your diet, that is). 4 minutes, or 7 minutes or 10 minutes – any of these minimalist workouts we see advertised all over the place simply aren’t going to cut it.

Consider first that how many calories you burn depends on your body size. Remember what we said earlier about bigger people burning more calories? That’s true during exercise as well as at rest (basal metabolism). Unless you’re a big, tall man, you probably don’t burn as many calories as you think from training.

Second, consider that the number of calories you burn doing Tabatas or other types of HIIT depends on the exercise you choose. If you do something easy like bodyweight-only squats, will you burn 20 calories per minute? No way. Will you achieve a huge afterburn? No. The way Tabata was done in the original research was all-out bicycle sprints to the point of vomitous exhaustion.

That brings up a third point. Many people can’t handle sprint-level intensity. They’re physically incapable, it makes them nauseous, or they simply hate it. The best workout is a lot like the best diet – it’s the one you like, can tolerate, and stick to consistently.

HIIT advocates often insist that the only cardio worth doing is intense. The truth is, studies show that you can burn just as much body fat with low or moderate intensity cardio as you can with high intensity cardio – it simply takes longer. Intense cardio is more efficient, but not necessarily more effective.

So you see, when it comes to fat loss, there’s no real shortcut, either way. If you don’t have much time, you have to work really hard. If you don’t want to work really hard, you have to work longer.

Last but not least, remember that fat loss from exercise is a function of total calorie burn. Total calorie burn is a function of frequency times duration times intensity, not intensity alone. You can increase your fat loss by turning up the dial on any one of those variables. You can also do it without ever worrying about the number of calories you burn, simply adjust your training volume based on your results each week.

More importantly, adjust your diet. As you’ve discovered after reading this list of inconvenient truths, focusing on calories burned at each workout may not be such a great idea.

Keep up your training – weight training and cardio training. But the real key to fat loss success is to control your diet by focusing on the number of calories you eat every day and making sure you have a calorie deficit.

And that’s the whole truth and nothing but the truth.