For women who are emailing me with “I’m not losing weight even though I eat 1200 kcal and exercise A LOT”: well, just let me call that what it is: bullshit. After reading this article, you’ll be ready to kickstart your weight loss journey
In Pixar’s Toy Story 2, Woody’s kidnapper, Al McWhiggin calls the cleaner to repair Woody when the toy’s arm falls off. Al asks The Cleaner: “So, uh, how long is this gonna take?” And The Cleaner replies: “You can’t rush art.”
But you did. You rushed fat loss on a 1200 kcal cookie-cutter diet. 3 weeks later, you plateaued. You now think of having a slow metabolism and being doomed to the faith of obesity.
Sorry to burst your bubble, buddy, but your metabolism is very likely to be as good as it has ever been.
Let me dive into the evidence first and then, I’ll show you 3 reasons you are not losing weight. Sounds about right?
“My Slow Metabolism Drives Me Bugshit Bonkers!”
If you’ve read some of my stuff, you already know what metabolism is. If you’re new here, metabolism is the whole range of biochemical processes that occur within you and require energy1.
Now, the determinants of total metabolic rate are divided up into:
- BMR (Basal metabolic rate): calories burned to run your body if, say, you’re in a coma;
- TEF (Thermic effect of food): calories burned from eating. On average, it’s about 10% of your total daily caloric intake but it depends on the nutrients eaten;
- NEAT (Non-Exercise Activity Thermogenesis): calories you burn moving around, fidgeting, changing postures. It varies massively from person to person;
- TEE (Thermic effect of exercise): calories burned through exercise.

As soon as you get your butt in gear and start dieting, all 4 respond:
- BMR plummets as you lose weight because a smaller body burns fewer calories;
- TEF drops too since you are eating less food;
- Since you have already lost some weight, calories burned during exercise decrease because a smaller person burns fewer calories;
- NEAT usually drops as you become more lethargic and end up moving around less.
What started as a 500 calorie per day deficit has dropped to 300 or 250 calories per day. Eventually, comes a point when you plateau. You’re eating just like you did before, a barbell is crushing your trachea during bench press and yet, fat isn’t moving anywhere.
The question you have for me is this: “can all these drops in metabolic rate be sufficient to completely offset my weight loss?“
The answer is: Hell NO. Not a single study in humans in 50 years shown stalled fat loss when calorie deficit was controlled.
The (in)famous Minnesota Semi-Starvation Study illustrates this brilliantly. War objectors avoided going to war and surely got into something worse.

Men were put on a 50% calorie deficit (cookie-cutter diet, if you ask me). They also performed daily activity (walking, no weight training) for 6 months. By the end of the study, the drop in metabolic rate was about 40%. This is the biggest drop in metabolic rate ever recorded.
Of that 40% drop, 25% was due to the reduced body weight (which is normal) and only 15% due to drops in BMR, TEF, TEE, NEAT. So even 6 months later, the subjects still had a calorie deficit of 10%.
Here is the kicker. The subjects also reached the limits of human leanness of 4-5% body fat. Without ever PLEATEAUING!
Don’t look at me like that. I don’t make science. I just report it. Your metabolism is just fine. It can’t slow down so much that fat loss stops.
This brings me to the first and the most crucial reason of why you are not losing weight…
You’re Misreporting Caloric Intake
Both you and I, even registered dietitians are horrible at estimating calorie intake. We suck at it. Dieters tend to under-report food intake to the extent that it seems a bit outside the realm of reality.
A now-famous 1992 study2, examined individuals who reported an inability to lose weight when being on a 1200 kcal diet. When tested, their metabolisms were normal.
Here is the punchline: their actual daily caloric intake was ~2081 kcal!
Breathing and living nutrition as your career also isn’t a guarantee you know how much you’re eating.
A 2002 study3 took 10 dietitians and 10 non-dietitians and looked at their food intake. Non-dietitians under-reported by an average of 429 kcal. Dietitians still under-reported by 223 kcal. Surprisingly (NOT REALLY), a few non-dietitians under-reported their intake by over 1,000 kcal!

But lean people must be good at tracking food intake, right? Nope. Normal-weight women under-reported4 food intake by ~22%. Overweight women by ~35%.
Something on the order of forty-eleven gajillion studies supports the fact that guestimating doesn’t work. This has been proven time5 after time6, after time7, after time8. Oh, here’s one more9.
Please, for the love of God, download a calorie tracking app and track every morsel of food that you put in your mouth (hire me to help you with that, maybe?).
Also, I’ve written an article to help you get started. You’re welcome.
You Think You’re Burning More Calories Than You Actually Are
How many calories do you think an hour of intense weight lifting burns if you’re 150-pound female? What? Did you say 700? 600? Uh, no. It’s about 265 kcal.
Here is an approximation of how many calories 150-pound female burns in various popular activities:
- Walking at 4 mph – 212 kcal;
- Aerobic classes (low impact) – 212 kcal;
- Weightlifting (intense) – 265 kcal;
- Aerobic classes (high impact) – 318 kcal;
- Stationary bike (moderate effort) – 318 kcal;
- Circuit training, including aerobic stations (with no rest) – 371 kcal;
- Jogging at 5.2 mph (slow) – 424 kcal;
- Running at 6 mph – 477 kcal
*(Taken from Essentials of Strength Training and Conditioning book).
No wonder why the subjects over-reported caloric expenditure via exercise by a humongous 51% in this study10.
Over-reporting caloric expenditure isn’t a big deal, though. The problem is that you burn 300 calories on a treadmill, feel you’ve earned yourself a reward, and then eat 500 calories worth of pizza.
“Because I exercised”.
Three little words that need to be put on an electric chair. People do a little exercise and then overeat because they rationalize they have earned themselves a reward. More studies are supporting this than Cosmo has freaky sex tips.
Holy Moses, just reading about exercise could lead you to eat more snacks11.
Summary: The goal of the exercise, strength training specifically, is to get stronger so you can maintain or even build muscle. Ditch your Fitbit, kick back, relax and ignore calories you burn via exercise. Imagine you burn 0 calories because a calorie deficit from a diet will take care of the fat-burning part.
Your NEAT Levels Have Decreased
NEAT is the reason why you hear your friend blaming “slowed” or “damaged” metabolism when the weight loss stalls. Maintaining an awareness of the potential impact of dieting on NEAT can go a long way toward maintaining progress.
I mentioned earlier that NEAT is just a fancy-schmancy way of saying that it’s all calories you burn outside formal exercise. Walking the dog, going to work or school, shoveling snow, playing guitar, dancing in the shower, etc.
Can you recall 4 determinants of total metabolic rate? NEAT is the ONLY one that you have control over. Also, NEAT varies substantially and it accounts for up to 2,000 kcal per day depending on your occupation12.
If the obese volunteers adopted the NEAT-enhanced behavior of their lean counterparts, they could expend an additional 350 kcal per day. Over a year, this alone could result in a weight loss of ~15 kg, if energy intake remained unchanged.
Concluded another study13
Here is the punchline. If you train for an hour a day, that only accounts for 4% of your day. The rest of your time awake makes up 63% of your day. That’s 63% of the time you have an opportunity to get more movement in your life.
So, for the love of God, stop killing brain cells with TV.
If you have an active job, your NEAT is going to be high enough. If you have a desk job, it can be easy to go the entire day with very little movement. Which is why it’s so crucial to get some additional movement in.
Walk your dog more than once a day, walk to the gym instead of driving, park far away from the gate, take frequent breaks at work to move, etc. During an eight-hour workday, all of these small actions add up!

Consider this fun factoid. The other day, the elevator going down from my gym didn’t work. Again, one that goes DOWN. Guess what? 7 out of 10 people turned around and looked for a lift.
Apparently, walking down the 20-stair elevator is too exhausting these days. Please, you can do better than that.
P.S. Make sure to read the order of priorities to lose fat article.

You are misreporting calorie intake and aren’t moving enough outside the gym. That’s why you can’t lose weight.
If I had your calorie intake controlled, you would get heart palpitations from seeing how much you actually eat (hire me as your coach, maybe, huh?).
Stop whining about your metabolism. Yes, you might not be blessed like I am with 3,200 kcal metabolism but it doesn’t excuse you from tracking food intake, getting daily steps and working on improving your health, fitness and body composition.