The 500 calorie deficit myth

At the risk of ad hominem, the author's own reply to her article:
"Thanks for your comments everyone, but take a look around. The population has never eaten so little and yet been so stricken by obesity-related disease. Sure, if you dramatically change your macronutrient and general food quality intake as a result of counting calories, then you will have success. But sadly most calorie counters fall foul of the enormous marketing machine that is the 'low calorie' food industry, and subsequently end up living on high sugar, high sweetener, nutrientless processed rubbish in order to get as much (sweet/refined) bang for their calorie quota buck as possible. These are the exact foods which equate to toxins in the body and which trigger insulin release and subsequent fat storage."

Cuckoo.

Anyone that raves about metabolism, toxins, and negative calorie foods should exit the realm of reality and go on Dr. Oz's show. One time I saw a blog about how apples don't have calories, another post about how Nutrisystem eliminates toxins, and an ad for an appetite suppressant that burns calories for you. Sometimes it's time to just turn off the internet.

The theory suggests that, if I were to cut my calories by 500kcals per day, say from 2000 to 1500kcal (more than what most modern day diets recommend), I would lose 1lb (of pure fat) per week. If I did that for 1 year I would have lost 52lbs, which is nearly 4 stone. I can categorically tell you that if I ate 1500kcals per day for the next year I would not end up weighing in at around 5 stone. So why do we still believe that this is the way to lose fat?

This part is where a lot or misconceptions happen, I think. The 500 calorie deficit isn't about cutting 500 calories from what you were consuming before; it is 500 calories cut from what your body uses in a day. So if your body uses 2000 calories a day in breathing, pumping blood, running, walking, talking, and doing whatever you do in a day, then yes, consuming 1500 calories a day will drop you by about a pound in week. But it's quite difficult to figure out exactly how many calories you burn in a day, and since this expenditure depends on so many biological and environmental factors, it varies not only from person to person, but day to day, especially as your body mass changes. That's why the math seems so fuzzy.

Also, the extrapolation here doesn't work because the body isn't made up entirely of fat. The 500 cal/lb formula doesn't hold for lean body mass.

When you go on a calorie restricted diet and you end up, weeks or months later, weighing more than you did initially, this is not you defying science. Nor is it you being weak-willed. When it comes to weight loss, your body is trying to look out for you, and will try and keep you alive as best it can. If you deny it calories it will shut everything down and get rid of the one thing that keeps you lean, your muscle tissue.

Counting calories does not work, and we need to understand that before we really commit to what will (more on that to follow!).

References

Harcombe, Z (2010) The Obesity Epidemic. Comlumbus Publishing Ltd.

Tucker, Todd (2006). The Great Starvation Experiment: Ancel Keys and the Men Who Starved for Science. New York: Free Press.

Excellent article. Thanks for posting it!

At the risk of ad hominem, the author's own reply to her article:
"Thanks for your comments everyone, but take a look around. The population has never eaten so little and yet been so stricken by obesity-related disease. Sure, if you dramatically change your macronutrient and general food quality intake as a result of counting calories, then you will have success. But sadly most calorie counters fall foul of the enormous marketing machine that is the 'low calorie' food industry, and subsequently end up living on high sugar, high sweetener, nutrientless processed rubbish in order to get as much (sweet/refined) bang for their calorie quota buck as possible. These are the exact foods which equate to toxins in the body and which trigger insulin release and subsequent fat storage."

Cuckoo.

thanks.

To your body, you have a lot of expendable muscle. Fat is the last-resort emergency back-up. When faced with a calorie deficit, your body will go to muscle first, since it's metabolically "expensive".

I don't think so. Muscle only 'costs' 6-10 calories/day per pound, and only provides around 600 per pound. Fat supplies around 3500 calories per pound. And obviously muscle is useful tissue whereas fat is primarily there for calorie storage. The body burns glycogen first, then fat, and protein (muscle) as a last resort, I believe.

I think the big lesson from ALL the studies is that no one can really know what any one person's metabolism is doing. They can look at overall average numbers from large groups of people to try to predict the outcome - but when it's you on your own diet/fitness plan, you don't know whether you're exactly average, or leaning towards one end or the other of the spectrum - ESPECIALLY when you consider that your own metabolism will change as your body adjusts to the diet, so even that isn't ever 100% known at any time either.

The only thing you can do is choose a healthy diet/fitness plan that works for you, and stick with it long enough to ascertain whether it is working, and then make adjustments in physical activity and calories to correct your metabolism, which will change as your diet does.

Yep. great post and in full agreement. Finding the right diet/fitness plan that works for you takes a lot of trail and error.

such a ridiculous post and still so many comments.
you must be really enjoying this.
typical of MFP anyway :yawn: :yawn: :yawn: :yawn: :yawn: :yawn:

one thing to add, is that for me I do not need to eat back all the calories I use exercising. If I am aiming for 1600 a day and run 10k (approx 1000 calories theoretically for me) I aim only to eat back half of those, as I am very fit (but overweight) and have been doing tons of exercise for years. (Average in 2013 was 1000 cals per day of exercise)

I bet I could find a random Internet blog proving the Loch Ness monsters existence too. It's probably just as convincing to me as some random idiot via interweb insisting that thermodynamics isn't real and the only reason they aren't losing weight is due to a mystical voodoo curse involving toxins, sugar, and a "broken" metabolism.

OP, I'm at a healthy weight at 121 lbs at 5'3.5", yet I can lose weight on 1900 calories a day with moderate exercise. It's not because I sprinkle my pop tarts with magic. It's because I'm creating a calorie deficit by being 100% honest with everything I log in my diary. While I think it is important to have a balanced diet involving nutrient dense foods, the idea that the quality, rather than quantity matters in terms of weight loss makes no sense. Will an imbalanced diet make me feel like poo? Yes. Will it hinder my weight loss? No.

saving to read later

Instead of spending all of that time "researching" a study on starving men, the OP should've spent the time to read and educate about nutrition, BMR, TDEE, from actual books. There is soooo much information available online also. I startedy journey years ago when I bought the clean eating diet by tosca reno. When you're educated about what is good for your body and what is harmful, you're less likely to just follow a diet plan that could harm you eventually. MFP calculates a calorie plan based on what you want but doesn't not encourage you to eat below bmr. Yeah you'll lose weight with a calorie deficit, but everyone needs to understand nutrition is extremely important. I love how MFP includes nutritional counts. It's made me realize some things I'm not getting enough of. MFP is a great way to start a fitness plan and a great way to get back on track if you've been eating extra without realizing. Tracking my food has always worked for me when I need to lose. I don't have unrealistic goals or expectations, and like everything else you need patience. It's a great platform for starting new and getting encouragement from others on the journey. I encourage everyone to read as much as you can about fitness and nutrition. Fitness magazines are fun reads for me and provide me with with incentives when I see others success stories. If everyone was more educated you would see less unhealthy fad diets.

It depends on each individual I think, like someone said, the men in this experiment were of a healthy weight, so Im assuming their bmi wasnt over rated. A person that has an obese BMI might benefit from fewer calories in their diet, teaches us self control and smart eating, when we reach a healthy weight, we should maintain it by eating our BMR calories. (Im here with an OBESE BMI but from pregnancy weight) I have done a low calorie intake in the past whilst obese and have lost unwanted weight and maintained by eating my BMR. Now, if a perfectly healthy person wants to lose a few stubborn lbs, then I suggest changing their eating habits, reduce process foods, increase fruit and veg(5 portions as recommended) and add exercise. In short, a 500 cal deficit is just a guideline in my opinion, you need to listen to your body and see what is best for it.
I hate how ppl sometimes think that because guidelines are set, they must be followed to the letter, there is also another myth involving breastfeeding mothers should eat 500 calories extra a diet which is a lot of rubbish. I eat 1000 a day, full of fruit and veggies and leans and my milk supply is plenty and my baby is a heavy chunky boy!:D

You should not be maintaining on your BMR calories. That would be your maintenance if you never moved at all.

Also I hope you're being monitored by a doctor to be eating so little while breastfeeding. It's incredibly difficult if not impossible to get all the nutrients you and your baby need on that intake.

I got as far as if I cut 500 calories I wouldn't lose 4 stone........ I did and I did so I am not reading anymore. Everyone is different and studies are good for research but everyone needs to know how their own body and metabolism works, and thats by trial and error.

Things that are true in that blog...
1. 3500cal per pound is an estimate.
2. The body loses a mix of fat and muscle.
3. Weight loss is not truly linear.
4. The study referenced existed.

Things that are false in that blog...
Everything not listed above.

spot on, exactly my point, ppl like to judge too quick, every one is different individual. guidelines are just that, guidelines, nothing written on stone.