How weight loss attempts backfire
You may have heard that diets don't work, but you may not fully understand why. After all, most people can eat less and move more and will lose weight!
It's true, short-term weight loss is possible for most people. However, after the body loses a certain amount of weight, a variety of compensatory mechanisms kick into high gear to restore us to what is known as our "set point range". This is the weight range where each individual's body feels happiest, and it occurs when you eat intuitively.
Essentially, as we lose weight, our body realizes, "whoa, I'm starving!" and it does everything it can to gain weight to the point where it feels comfortable again. Just like our bodies maintain homeostasis with regard to things like our internal temperature, they also like to maintain our weight.
These weight loss-induced compensatory mechanisms, which are orchestrated by a part of our brain known as the hypothalamus, are the reason why in a major meta-analysis of dieting studies, the average amount of weight lost was a mere 0.9 kg.1 Our bodies fight against us the moment they see our weight shift significantly lower.
(It's also valuable to note that the average weight lost in dieting studies is likely artificially high, due to most weight loss studies having major design flaws. Factors in this include subject selection biases, people dropping out due to the shame of weight gain, poor data gathering, and people going on multiple diets in succession!)2
Read on to understand each of them in more detail.
When you diet to lose weight...
1) Your brain notices food more.
Kinda cruel, isn't it? But it's true: when you are depriving yourself of food, your brain actually starts to notice food more.3
Not only that — your brain pays more attention to the food when it comes across it. This is all done by the amazing hypothalamus and a variety of hormones.
2) Your tastes change so more foods are appealing.
Dieting even leads to our hypothalamus to change the way we perceive tastes so a wider variety of food is appealing.
It can also make you want high fat food more, because fat contains more calories than other macronutrients. 4
3) Your appetite increases & you feel less satiated when you eat.
Losing weight leads to a reduction in the hormones that help you feel full (leptin, peptide YY, and cholecystokinen).
As if that weren't enough, it also leads to an increase in the hormones that make you feel hungry (ghrelin, gastric inhibitory polypeptide, and pancreatic polypeptide).5
These hormonal changes have been shown to be long-lasting; for instance, once study showed they last at least a year past the end of someone's diet!6
4) Your muscle tissue is decreased and fat tissue is increased to save energy
Our muscle tissue is active tissue that uses a lot of energy (more energy than our fat). When we lose weight, our bodies actively reduce the amount of muscle in our body so it uses less energy overall!7
Simultaneously, our body releases enzymes that promote fat storage and reduce the release of fat.8
5) Your metabolism slows down
Losing weight reduces your leptin, as mentioned earlier, and this functions to make your metabolism more efficient, doing more with less (we think of this has having our metabolism "slowed down").
One study found that people who diet their way down to a certain weight must take in 25% fewer calories to maintain that weight than people who are the same weight but haven't dieted to get there.9 This is the body trying to conserve energy because it believes it is experiencing a famine.
Studies of the Biggest Loser contestants showed that they consistently require hundreds fewer calories per day than other people their weight; for instance, Danny Cahill now burns 800 calories a day fewer than other people his size.
Leptin can stay chronically low after repeated dieting attempts, which can lead to weight gain over time, even past one's starting weight.10
Wondering if your metabolism has slowed? One signal of this can be that you're always cold, because your body is conserving energy by not circulating as much blood to your extremities.11
6) Your desire for movement decreases.
During and after weight loss, our trusty hypothalamus sends us messages to conserve energy by reducing our physical activity! Of course, a certain amount of willpower can overcome this, but this points to why it can feel like a major uphill battle to get to the gym when we're dieting.12
How Weight Loss Attempts Backfire: A Summary
Here's a nifty summary of all of the points above. Consider saving it somewhere you can refer to it if you have doubts pop up in the future. When we're first starting this work, before we've internalized the concepts, it's easy to have moments where we think, "ok, maybe I just didn't do the right diet / food philosophy / lifestyle change". This image will be here to reassure you that no, no matter what weight loss technique you try, long-term sustainability is not possible!
Let me also pause and make this really clear: if you have tried to lose weight and that weight eventually came back on, it is not your fault. You are not weak, lazy, or lacking in willpower! You regained the weight because your body really, really, really wants to stay within its set point weight range, and it employs these techniques to do so.
So if weight loss doesn't work, then what?
What’s left if we can lose weight? So much. So, so much. Liberation is on the other side of giving up dieting and weight loss! For instance, we can work on our relationships with food and our own bodies. We can strive to make peace, find trust, and experience embodiment. We can learn to see ourselves as worthy whatever the size or shape of our bodies, just for being us. We can slowly put back the pieces after being traumatized by fatphobia and diet culture.
Sources
Tomiyama, A. Janet, Britt Ahlstrom, and Traci Mann. "Long‐term Effects of Dieting: Is Weight Loss Related to Health?." Social and Personality Psychology Compass 7.12 (2013): 861-877.
Mann, Traci. Secrets from the Eating Lab: The Science of Weight Loss, the Myth of Willpower, and why You Should Never Diet Again. Harper Collins, 2015.
Stice, Eric, Kyle Burger, and Sonja Yokum. "Caloric deprivation increases responsivity of attention and reward brain regions to intake, anticipated intake, and images of palatable foods." Neuroimage 67 (2013): 322-330.
Bacon, Linda. Health at every size: The surprising truth about your weight. BenBella Books, 2010.
Sumithran, Priya, et al. "Long-term persistence of hormonal adaptations to weight loss." New England Journal of Medicine 365.17 (2011): 1597-1604.
Ibid.
Bacon, Linda. Health at every size: The surprising truth about your weight. BenBella Books, 2010.
Kern, Philip A., et al. "The effects of weight loss on the activity and expression of adipose-tissue lipoprotein lipase in very obese humans." New England journal of medicine 322.15 (1990): 1053-1059.
Leibel, Rudolph L., and Jules Hirsch. "Diminished energy requirements in reduced-obese patients." Metabolism 33.2 (1984): 164-170.
Ibid.
Bacon, Linda. Health at every size: The surprising truth about your weight. BenBella Books, 2010.
Ibid.