Geschatte leestijd: 7 minutenBoth losing weight and gaining weight are complicated by the principle of compensation: The body adapts to a shortage or surplus of nutrients by adjusting metabolism.
The Energy Balance
Losing weight and gaining weight result from a calorie deficit or surplus on the energy balance, respectively. If you expend more energy than you consume, you lose weight. If you consume more than you expend, you gain weight. So, to lose weight, you could either eat less or exercise more, while to gain weight, you eat more or exercise less. That’s the well-known and straightforward theory. Although I wrote an article two weeks ago titled “Losing Weight is Simple” (I & II), in practice, there are a few caveats to consider.
We wrote yesterday that losing weight is not linear. The compensatory effect of the body on a diet is very likely the biggest cause of this.
Why Losing Weight is Difficult: Compensation for Energy Deficit
Our bodies have very different priorities than we do (or think we do). While we may think of a six-pack, the body thinks of survival. While we may think of muscular shoulders, the body thinks of survival. While we may think of nice buttocks, the body, again, thinks of survival. Granted, appearance is important for reproduction. However, when the body has to choose between survival and looking good, the choice is quickly made.
Looking good is then a matter for later when there’s no crisis.
One consequence of this is that the resting metabolism is lowered, and your body becomes more efficient with energy when less is coming in. Similar to a sports car that could adjust its fuel consumption based on the amount of gas in the tank. Without this mechanism, most of us or even all of humanity would not exist. In all situations where people had to perform hard labor and didn’t get enough food, they would perish if the body couldn’t lower the need for food by reducing energy consumption.
This principle of compensation is fantastic if you’re in a Siberian labor camp, had to survive the hunger winter of ’44-’45 on two turnips, only get peppernuts to eat while being against Black Pete, or don’t like Chinese food while being in China. The fact that famine still occurs in the world means that this principle of compensation probably still saves lives daily.
Why Gaining Weight Doesn’t Happen as Quickly as Expected
Conversely, your body will actually burn more energy when more is coming in [3]. Bodybuilders know they have to eat more and more to keep building muscle mass as they get bigger. After all, the more muscles they have, the more energy they consume [4,5]. The same diet won’t produce the same results because the demand has increased. However, you’ll also see the same effect with people whose weight has increased due to body fat.
This is also known as the “law of diminishing returns.” One might wonder what the world would look like if this principle didn’t work this way. People who are so heavy now that a wall needs to be broken down to move them have “achieved” this despite their body actively working against it. Without that brake, they would be even heavier or (more likely) have already died from the consequences of their obesity.
Why a Calorie Deficit Often Results in Less Weight Loss Than Expected
However, deliberately creating a calorie deficit to lose weight can also work against you. Research shows that especially women “suffer” from this. In a 2003 study from the University of Kansas, for example, where men lost weight (by compensating for a surplus of calories with more exercise, resulting in a deficit), the women saw no results [1]. For sixteen months, they maintained a daily calorie deficit of 200 kcal by cycling and walking more. However, this did not result in weight loss for the women. However, it saved them from gaining the extra three kilos that the control group (who ate the same and didn’t exercise more) gained in weight. The men, however, lost an average of 5.2 kilos in those sixteen months.
The researchers suspect that this difference between men and women was caused by the fact that women’s bodies compensate more than men’s bodies do.
Why Losing Weight is Difficult: Yo-Yo Effect
You may also wonder what happens to the weight of women (and men) when they stop exercising. Their energy expenditure has decreased, so they will notice a period when they gain weight faster than before they started the study while eating the same. The question is how long such a period lasts, but it cannot be ruled out that this ultimately nullifies the “result” (they didn’t lose weight, but also didn’t gain) entirely. The “yo-yo effect,” accelerated weight gain after ending a diet, can thus be seen as the “aftermath” of the previous diet’s compensation. Your body used less energy and continues to do so for a while when more food is consumed again, causing you to gain weight faster than when your body was used to the larger amount of food.
Metabolism Change Due to Energy Balance Change
Researchers from New York studied what happens when you let people with and without overweight eat 10% more or less than necessary to maintain their weight for a while [3].
Consuming 10% less food on average resulted in people with a normal weight burning on average 6 kcal less per kilo of lean body mass daily. For people with overweight, this was on average 8 kcal less. I’ve highlighted “per kilo of lean body mass” because it’s not simply that less is burned because there’s less mass, but effectively less is burned per kilo (lean body mass).
Conversely, consuming 10% more food resulted in people without overweight burning on average 9 kcal per kilo of lean body mass more. In people with overweight, this was on average 8% more.
In plain terms, if you already have overweight, your body adapts more to a diet with fewer calories, making it less likely to lead to weight loss. That’s a bummer for people with overweight. On the other hand, during weight gain, the body has also tried to work against this by increasing combustion. If this compensatory effect hadn’t occurred, you would have gained even more weight beforehand and would have had even more overweight (which would also have disappeared more quickly if you ate less).
Maintenance of a reduced or elevated body weight is associated with compensatory changes in energy expenditure, which oppose the maintenance of a body weight that is different from the usual weight. These compensatory changes may account for the poor long-term efficacy of treatments for obesity.
R.L. Leibel, Rockefeller University
No Exact Calculation
In theory, you can calculate exactly what the calorie requirement is and how much an energy deficit or surplus is [5]. However, in practice, this is more difficult and still quite expensive to have this calculated exactly on a personal basis. Even if you accurately calculate an energy deficit or surplus, it doesn’t mean you know how much weight you will lose or gain [2].
In theory, a calorie deficit of 3500 kcal should result in a weight loss of one pound [2]. If you were to eat 500 kcal less per day than you expend (or vice versa) for a week, that should result in slightly less than half a kilo of weight loss after 7 days. In practice, however, this turns out to be less straightforward. Moreover, the differences between various individuals are considerable.
It is apparent that the expected weight loss when calculated from energy expenditure of exercise is usually greater than what is actually observed.
J.E. Donnelly, University of Kansas
As I mentioned in the aforementioned articles “Losing Weight is Simple,” calculating your calorie requirement is only the best possible approximation of your actual requirement based on standardized data. Excellent to start with, but not very effective without regular evaluation and possible adjustment based on your personal results. It may turn out that a deficit of 200 kcal per day initially leads to results, but not after a few weeks.
Losing Weight and Gaining Weight Becomes Increasingly Difficult, But That’s Better Than the Opposite
The longer you are involved in losing weight, the more effort you have to put into it, and the same goes for gaining weight. But that’s better than the other way around.
Losing weight and gaining weight often happen relatively quickly in the beginning. “Newbie gains” is an expression for the rapid increase in muscle mass that beginners can have when they start with strength training and an adjusted diet. Quick and large increases they later nostalgically remember because they will never achieve such results in such a short time again. However, the fact that the results came so quickly in the beginning was incredibly motivating. You almost see yourself grow in the mirror and think, “I want this every day!” And so you step into the gym again the next day. By the time the results don’t come as quickly anymore, chances are you’re already used to your training and diet schedule, making it easier to stick to despite less spectacular results.
Imagine if it were the other way around and it was physically more difficult to lose weight or gain weight in the beginning. Just when it’s mentally the hardest because you have to break your habits, you would hardly see the effects of it. Then that motivation would quickly disappear. In that respect, it’s handy that your body cooperates the most when motivation, habit, and discipline are least cooperative and vice versa.
Conclusion: Why Losing Weight is Difficult
I therefore agree with Mart’s conclusion in his article: If you really want to achieve results, know that this requires a plan and commitment for the long term. Also, realize that as you progress, it will require proportionally more effort.
References
- Donnelly, JE, Hill, JO, Jacobsen, DJ, Potteiger, J, Sullivan, DK, Johnson, SL, Heelan, K, Hise,
M, Fennessey, PV, and Sonko, B. Effects of a 16-month randomized controlled exercise trial on
body weight and composition in young, overweight men and women: the Midwest Exercise
Trial. Arch. Intern. Med. 163: 1343-1350, 2003. - Donnelly, JE, and Smith, BK. Is exercise effective for weight loss with ad libitum diet?
Energy balance, compensation, and gender differences. Exerc. Sport Sci. Rev. 33: 169-174, 2005. - Leibel, R.L., M. Rosenbaum, and J. Hirsch. Changes in energy expenditure resulting from altered body weight. N. Engl. J. Med. 332:621–628, 1995.
- F Zurlo, K Larson, C Bogardus, and E RavussinSkeletal muscle metabolism is a major determinant of resting energy expenditure.
J Clin Invest. Nov 1990; 86(5): 1423–1427. - Nelson KM, Weinsier RL, Long CL, Schutz Y. Prediction of resting energy expenditure from fat-free mass and fat mass. Am J Clin Nutr. 1992 Nov;56(5):848-56. PubMed PMID: 1415003.
