You did everything right. You planned meals, you moved your body, and you prioritised sleep. You felt great, and you lost weight. But then, one day the weight came back—and now you can’t seem to get it off. What gives?
If it feels like your body is working against you, it could have something to do with your set point weight. And understanding how it works could be the key to overcoming it—and to maintaining— your weight loss for the long term.
So, what is your set point weight?
Set point weight, or “settling point” weight, posits that your body has a predisposition for a certain weight. And that set point weight is different for everyone. It’s one reason why some people with obesity find it so challenging to lose weight: Their body may have a set point of 120 kilograms while someone else has a set point of 80 kilograms, and going below that number feels like fighting against their own nature.
“We think everyone has a set point, or amount of fat, that should be in normal ranges, and if you vary from that, the body will defend that set point to get it back to where it was,” says Robert F. Kushner, MD, professor of medicine in endocrinology and medical education at Northwestern University Feinberg School of Medicine in Chicago, United States.
Though it’s still a theory, most experts agree that set point weight is legit—but the exact reason it happens is still up for debate, says Steven B. Heymsfield, MD, professor at Pennington Biomedical Research Center in LA, United States. He says that while there has yet to be proof of an internal thermostat for body weight, there is real evidence to show that people tend to keep their weight fairly consistent over long periods of time.
What can affect your set point?
Your set point may be regulated by the body, but it’s not necessarily stuck at one setting. Here are things that may affect it:
1/ Your brain
Your set point is largely determined by the appetite centres of the brain, says Kushner. Essentially your brain may keep tabs on the amount of fat in your body and adjust factors like your appetite in response to weight loss or gain. If you lose fat, your appetite goes up; if you gain fat, your appetite, in theory, goes back down.
2/ Genetics
“We know that genetics drives a lot of how much someone weighs, just like it determines hair and eye colour,” says Kushner. In fact, about half of your weight is regulated by genes that affect factors like appetite and insulin function—how well your body converts glucose to energy. The other half comes from outside forces, like the calories (a.k.a. kilojoules) you eat and what you burn through activity. Genetics definitely play a role in obesity, with one classic study showing that twins who were raised apart had similar body mass indexes regardless of the kind of environment they grew up in.
3/ How quickly (or slowly) you gained weight
Short-term weight gain (like what happens when you get pregnant) may be less detrimental to your set point than a slow and progressive weight creep caused by decades spent at a desk job, excess stress, and unhealthy eating habits, says Kushner.
4/ Hormones
Hormones tend to act like backseat drivers. As you exercise, change your diet, and focus on losing weight, your body reacts by releasing a hormone called ghrelin, which makes you feel hungrier. Simultaneously, your body pumps out less of a hormone called leptin, which makes you feel full. The interactions between these hormones and your body can affect your set point.
5/ Weight-loss treatments
Both weight loss medications and surgery seem to affect one’s set point weight, says Kushner. “The most effective way to adjust the set point is to work biologically, and that’s what these treatments do,” he says. This is one reason why weight-loss medications can be an effective treatment for obesity in addition to lifestyle changes.
6/ Medications
Certain medications that you take for health conditions can cause weight gain as a side effect and affect your set point, says Kushner. Talk to your doctor if you’re experiencing a weight change after starting a new medication that you’re concerned about.
7/ Disordered Eating
If you have a history of periods of restricted eating that results in you falling below your natural set point weight, your body hits survival mode. Hunger signals and food thoughts can increase, while your metabolism slows. All of this happens as a result of evolution to help protect us from starvation.
Can you lower your set point weight?
While gaining weight slowly over the years can reset your set point to a higher weight, decreasing it can take some effort. Here’s why: Let’s say, in order to lose weight, you reduce the number of calories you’re eating and increase your physical activity level. As a result, you lose body fat. That triggers certain adaptations, such as an increase in appetite.
“What’s driving that is your body trying to get you back up to the weight you were when starting your new healthy habits,” says Kushner. On top of that, when you lose weight, your metabolism slows and you naturally need fewer calories to function, so you need to recalibrate your eating habits accordingly to maintain any weight loss.
So what can you do to successfully lower your set point? Slow and steady weight loss through behavioural changes is key. One study found that the more consistent you are at the beginning of your weight-loss journey, the likelier you are to keep the weight off over the long term. In fact, consistency mattered more than how much weight you lost in the first six or 12 weeks of following a healthier lifestyle. And researchers at Ohio State Wexner Medical Center found that off-and-on fad diets—which are the opposite of consistent—are rarely successful at helping people maintain weight loss because they slow metabolism, increase the hunger hormone (ghrelin) and decrease the “I feel full” hormone (leptin).
How to sustain weight loss
To shift your set point down, consider these five science-backed strategies:
- Set the right goal: Having a smaller, achievable goal can help you stay motivated with your healthy habits so that you keep at it for the long-term. Where to start? Aim to lose 5% of your body weight.
- Track your food: You may have the hang of this already–especially if you’re on WeightWatchers, which offers an in-app food tracker—but try to keep tracking what you eat even once you reach your goal weight. WeightWatchers members can expect to lose 0.5 - 1 kilogram/week, and research shows that this type of self-monitoring was key in people who kept weight off.
- Know your hunger: It’s physiologically normal to feel hungry, and you can expect some hunger when you’re losing weight and after, says Heymsfield, as your body gets used to its new normal. Simply recognising that hunger is a normal feeling that you don’t immediately need to get rid of can help, as can understanding the difference between physical and emotion-based hunger.
- Move your body: Healthy eating might drive weight loss, but physical activity keeps it off. After weight loss, your muscles are more efficient, meaning they burn fewer calories doing the same amount of activity. But exercise—particularly weight training—builds muscle and combats some of those adaptations, says Kushner. Research shows that people report burning an average of 383 calories daily through exercise to maintain their weight loss, while other studies suggest burning 1,500 to 2,000 calories per week to maintain your weight. Importantly, this doesn’t have to be a gym workout. Walking around the neighbourhood with a friend, doing bodyweight moves while watching TV, and playing a competitive game of tag with your kids all count.
- Plan well: Keeping good-for-you food at home is one strategy that sets people up for success to stay at their goal weight, because it puts healthy habits on autopilot—it isn’t challenging to choose fruit and yoghurt over a bowl of ice cream for a snack if you regularly stock up on the former and not the latter.
The bottom line
According to set point weight theory, the amount of fat you have is regulated by your body. Losing or gaining weight triggers adaptations in your body to push you back up or down to your original weight. Resetting your set point takes time and effort, but if you lose weight slow and steadily, you’re more likely to keep it off for good.
This content is for informational purposes only and does not constitute medical advice, diagnosis or treatment. It should not be regarded as a substitute for guidance from your healthcare provider.