Is it true to say that not all calories are created equal?
Mainstream media has a lot to say about whether all calories are equal. I had the daily news tuned in on the TV as I was preparing my food today, when again I overheard another medical doctor discuss how what you eat has more of an impact on your health, than how much you eat. This also reminds me of Dr. Oz and all those articles you can find about “super foods” when you do some simple Google searches.
Since obesity has been recognized as a statistical problem, many varying explanations have been popularized by all forms of media. I personally think it’s quite sad that so much more money is made from confusing our population, rather than telling the truth.
Let’s examine some of the top arguments for why not all calories are created equal:
Argument #1: Carbohydrates (Especially Sugar) Cause Fat Gain and Health Issues
This is an extremely popular point of view and is widely shared by many medical doctors. Of course, one of the most well-known origins comes from the famous Dr. Atkins revolution. Yes, it is true that Americans consume more carbohydrates today than ever before. It is also quite true that Americans are more overweight today than ever before. It is therefore easy to find statistical studies that link carbohydrate intake to obesity, and obesity related illnesses.
Medical experts are even able to biochemically demonstrate with great detail how increased carbohydrate/sugar intake leads to weight gain and related health complications. They conveniently, however, leave out the discussion about under which circumstances such might happen. In other words, this does not always happen, and actually rarely happens in normal healthy individuals.
In fact - none of the aforementioned data is actual evidence that reducing your carbohydrate and/or sugar intake will lead to weight loss and improved health. A statistical correlation is never causation.
Hu et al. conducted the largest strict meta-analysis of randomized controlled clinical trials (RCTs) of low-carbohydrate versus low-fat diets, in which they examined 23 studies and concluded that no significant differences were observed between the groups, in terms of weight, body composition, and metabolic risk factors .
What about the biochemistry that doctors so convincingly use to show us the harm carbohydrates cause? Well Tay and his team conducted a 24-week trial where one group consumed a high-carb diet, while the other a very-low-carb diet, but both groups consumed same caloric ratios. When controlled for calories, weight loss was similar in both groups, and metabolic factors improved as well. Interestingly, he found that the high-carb group had slightly better results on their lipid profiles .
Argument #2: We Must Watch Out for the Bad Fats
The majority of the medical community and all major health organizations still tell you to watch your fat intake, and especially to be wary of saturated fats. Just like with carbohydrates, population-based studies show that fat consumption has increased over the years, alongside with weight and heart disease. Does this mean that foods with fat should be avoided?
Pirozzo et al. examined long-term RCTs to assess whether there is any merit to the recommendations for low-fat diets. What they found was that when compared with traditional low-calorie diets, they were unable to distinctly find any differences in weight loss and health markers . Should we be surprised that high-calorie foods also have a lot of grams of fat and carbohydrates?
I don’t want to leave the scope of this article, but it’s important to understand three things which I will discuss in the future:
- Dietary fat/cholesterol does not necessarily equal body and blood fat/cholesterol.
- There is no evidence to suggest that certain types of fats are more harmful than others when the person in question has a healthy, well-balanced, calorie-controlled diet.
- Many people with high “bad” cholesterol are not at risk for heart disease, while many people with low “bad” cholesterol are. Something else seems to be going on.
Argument #3: Meal Frequency and Timing Matters
We have all heard the famous “eat more often to increase your metabolism and decrease appetite” advice. In my experience, almost everyone I know believes and follows it. There was a time when I believed it too and now I am called crazy many times when I say the opposite – but the data does not lie.
Cameron and his team designed a randomized 8-week calorie controlled diet, where one group consumed all calories in 3 meals, and the other doing so with 3 meals and 3 snacks. Not only was weight loss the same in both groups, but their measurements on gut peptides and appetite showed no differences as well .
To really seal the coffin shut on this case, you can look up studies regarding Ramadan practitioners and an entire sub-culture of dieting called “intermittent fasting .” You will find out how there are many benefits to going long periods without food, with the caveat that calories and macro-nutrients are controlled.
Argument #4: Some Macro-nutrients are harder to break down than others
It is completely correct that proteins are “harder” to digest than carbs and fats. More complex carbs are harder to break down than simpler ones. And yes, if it’s harder to metabolize, more energy is required, and thus leads to greater weight loss.
All this is true, but also irrelevant – because when we design for ourselves a calorie controlled diet, we are basing it on Total Daily Energy Expenditure (TDEE), which already incorporates the thermic effect of feeding (TEF). It would be way too complicated to attempt to calculate this each time when carrying out your daily eating plan.
Argument #5: If you eat too little, your body will go into “starvation mode”
This is actually a very interesting argument as well. We all heard about the famous starvation mode where your body will hold onto everything you eat in order to compensate for prolonged crash-dieting, and also burn muscle instead of fat.
Well – this just simply does not happen. There is no such thing as starvation mode. An energy (calorie) deficit, will always result in a net weight loss. When losing weight your body will always primarily burn body-fat, until you are down to the last essential body fat (~5% in men) .
Dr. Layne Norton discussed a more appropriate phenomenon called “metabolic adaptation” or even “metabolic damage .”
Your body will always try to maintain homeostasis. It is based on “set-point” theory that your body can and will drastically change after pro-longed extreme calorie deficits .
Let me be clear here. There is no evidence to suggest that your body will force you to gain weight from eating less. Metabolic adaptation does not even occur acutely (short-term). It is simply being observed that very long periods of eating too little (most often seen with physique competitors pre-competition) will lead to a drastically reduced metabolism .
Calories are not suddenly being ignored as that would be impossible. Instead – your body will utilize less energy, in order to allow itself to store more in the form of body fat; evolutionary adaptation at its best.
The people that experience a similar effect short-term are undergoing mental deprivation and stress from crash-dieting, which has been proven to lead to binge-eating, relapse, and even worse, depression. This is the cycle you most want to avoid.
So you don’t want to crash-diet short-term, and you certainly don’t want to have pro-longed periods of low-calorie eating either. That only leaves you with the option to eat a moderately reduced calorie diet for weight loss and think in terms of lifestyle and nothing else. Looks like the basics are still holding strong.
I want to conclude by simply saying that your body does not know the difference between apples, broccoli, chocolate, rice, soup, and chicken. It does not taste or feel texture once you swallow. Everything is broken down into calories by way of macro-nutrients: carbohydrates, proteins, fats, fiber, and into micro-nutrients: vitamins, minerals, antioxidants, etc.
The best recommendations are to create a long-term sustainable plan, one that does not leave you feeling deprived for any reason. Don’t waste your time believing the hype! Figure out your macro and caloric needs, and make sure you get sufficient fiber and micro-nutrients. Most importantly – enjoy your diet!
- Hu T, Mills KT, Yao L, Demanelis K, Eloustaz M, Yancy WS Jr, Kelly TN, He J, Bazzano LA. Effects of low-carbohydrate diets versus low-fat diets on metabolic risk factors: a meta-analysis of randomized controlled clinical trials. Am J Epidemiol. 2012 Oct 1;176 Suppl 7:S44-54
- Tay J, Brinkworth GD, Noakes M, Keogh J, Clifton PM. Metabolic effects of weight loss on a very-low-carbohydrate diet compared with an isocaloric high-carbohydrate diet in abdominally obese subjects.J Am Coll Cardiol [serial online]. 2008;51:59-67.
- Pirozzo S, Summerbell C, Cameron C, et al. Advice on low-fat diets for obesity. Cochrane Database Syst Rev.2002;(2):CD003640 (latest version 25 Feb 2002).
- Cameron, JD., Cyr, MJ., Doucet, E. (2009) Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8 week equi-energetic energy-restricted diet. British Journal of Nutrition. Nov 30:1-4
- Martin Berkhan. Leangains.com 2008
- Ancel Keys: Minnesota Starvation Experiment 1950: http://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment
- Eric T Trexler1, Abbie E Smith-Ryan1 and Layne E Norton, Metabolic adaptation to weight loss: implications for the athlete. Published February, 2014. http://www.jissn.com/content/11/1/7