Rebound weight gain is an inescapable “biological reality” said the New York Times, regarding the weight gain contestants on the show “The Biggest Loser” routinely experience. Published in Obesity, a recent study followed up with fourteen out of sixteen contestants in one of the seasons of the show, to observe how many participants kept the weight off and what happened to their resting metabolic rate (RMR).
Only one participant kept the weight off at the six-year follow-up. The average rebound weight gain was 2/3 of the initial weight lost. Five out of the fourteen participants were within 1% of their weight before the show started.
Their resting metabolic rates declined considerably as well. The researchers expected that with the rebound weight gain metabolism should have gone up too, but it didn’t at all. In fact, it seemed to decrease a little bit at the six-year follow-up.
Unfortunately, some participants join additional weight loss programs to keep the weight off. It an be very distressing to lose so much weight and gain it all back. But the harder you try to lose weight the harder it can become to keep it off. This is why it’s called yoyo dieting. The harder you throw the yo-yo, the faster it comes back up. The harder you try to lose weight, the faster it will come back up.
I’ve been curious about this lately, as I’ve experienced the same thing. I had abs once, back in the early 2010s. I was exercising very hard and routinely skipped my breakfasts to “intermittently fast.” I then ate sweet potatoes for breakfast because I thought they were healthier than white potatoes. I confused “healthy” with “fat-loss” as many people still do.
Leptin and fat
I recently came across an interesting paper that measured brain activity in response to pictures of food with or without leptin injections after 10% weight loss in obese subjects. Here is a run down of what happened:
1. Obese patients were shown pictures of food and their brains were scanned via an MRI.
2. They went on a calorie-restricted diet until they reached 10% weight loss.
3. One group of obese people received leptin injections and the other received saline. The amount of leptin injected was calibrated so that each subject’s leptin levels went up to the level it was at before weight loss.
4. After five weeks of daily injections, the subjects underwent another MRI with the food stimuli.
5. This five-week process was repeated again except the subjects switched groups. The group receiving leptin injections now got saline, and vice versa. The whole time the weight loss was maintained.
This cross-over study found that when obese people who lost weight received leptin, parts of the brain that regulate our emotional and cognitive functions of food (and cause cravings) didn’t light up as much as in the group who received saline injections (and thus had lower leptin levels).
So what do we do with this information?
The best thing to do to lose weight long term is to do it slowly. But if you have already lost weight and gained it back, stop trying to lose it. Stop restricting calories as this is doing nothing for your metabolism. Every time you try to lose weight again your body will try to gain it back.
Currently, I’m focusing on sleeping properly each night (which increases leptin and lowers cortisol), and eating when I’m hungry. In addition, I’m learning more yoga and meditate just to reduce stress, especially after working out. Since exercise is a stressor, I am making sure to workout based on how I feel and not push myself unnecessarily. Perhaps this will allow my metabolism to allow me to come back to a leaner weight in the future.