The supposedly simple equation for weight loss—calories in equals calories out—appears straightforward, but sometimes it feels like a bit of a mystery. Most people can lose a few pounds with diet and lifestyle changes, but keeping it off is more complex.
In reality, our ability to maintain a healthy weight looks more like a Venn diagram with overlapping circles of factors like stress, genetics, hormones, age, activity level, sleep, and diet. Still, some people seem to drop weight easily while others struggle—why?
There is no single explanation, but one idea is known as set point theory. Set point suggests there is a specific weight range that our body is biologically programmed to live within. This means that when we try to lose weight, it’s like we are fighting against our own physiology.
But is set point a real thing, and how can it affect your weight loss goals? Let’s dive into what the science says.
What Is Set Point Theory?
Set point theory<sup>1</sup> suggests that your body has a preferred weight range based on genetic, hormonal, and metabolic factors. Set point can influence how much energy is burned at rest, the efficiency of our metabolism, and hormones that control hunger and satiety.
Set point states that when you try to lose weight, your body will compensate through physiological changes that affect your metabolism by slowing down or speeding up energy expenditure. It also impacts appetite regulation, making it challenging to get beyond your predetermined number.
Set point weight may also have a genetic determinant<sup>2</sup> that helps shape your set point and ability to lose and maintain weight. According to set point theory, everyone is different, so some may have lower set points that make it easier to maintain weight loss.
Is There Scientific Evidence Supporting Set Point Weight?
Although it sounds reasonable, the evidence surrounding set point theory is mixed. On the one hand, it could help explain why people have such a hard time losing weight and keeping it off.
On the other hand, it doesn’t explain differences in rates of obesity like we see across different regions, cultures, and societies.
When it comes to weight loss, humans are challenging to study. Observational studies, where we monitor people to watch for a specific outcome, are commonly used in weight loss research. But these studies can’t always control all the other factors that could influence weight.
Instead, it may be more accurate to say that a set point could be one part of the complex equation of weight loss. There aren’t any specific landmark studies that emphatically conclude that set point theory is true, but there are clues that seem it could play a role.
Metabolism and Set Point Weight
For many people, cutting calories can slow down metabolism. This means you burn fewer calories throughout the day. It’s likely related to the body’s protective mechanism to conserve energy.
One meta-analysis that examined obese people who lost a significant amount of weight found that their resting metabolic rate (RMR), or the number of calories they burned at rest, was thee to five percent lower than matched controls<sup>3</sup> of people who weighed the same but were never obese.
However, another study that examined members of the national weight control registry (a study on people who lost weight and successfully kept it off for at least one year) found no difference in the RMR<sup>4</sup> between those who had lost weight and matched weight controls.
A study on postmenopausal women found that while restricting calories temporarily slowed metabolism, many women regained normal energy expenditure after resuming an energy-balance state<sup>5</sup>, suggesting they conserved energy when calories were scarce.
Theoretically, this means you’d have to adjust your food intake even more to continue losing weight. But if you’ve already cut calories significantly, it may not be realistic to drop further and doing so could stress your body out even more.
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Hormones and Set Point Weight
The way your body regulates weight may also be linked to signals sent to your brain by your fat and energy stores. As body fat changes, you may feel like eating more or less. An example of this is seen with the hormone leptin<sup>6</sup>.
Leptin, which is released by fat cells, stimulates receptors in an area of your brain (the hypothalamus) that regulates hunger. More leptin means you feel more satisfied and full and lower leptin levels signal hunger.
Leptin appears to protect you from losing too much fat<sup>7</sup> and can even decrease your energy expenditure<sup>8</sup>, or how many calories you burn.
Looking at it from an evolutionary lens, hormones like leptin protected humans against starvation<sup>9</sup> when food was scarce. But of course, we are no longer hunter-gathers searching for our food and live in a state of overabundance.
So as you lose body fat, leptin levels drop to help you conserve energy. At the same time, another hormone called ghrelin increases. Ghrelin is leptin’s opposite, stimulating hunger and appetite<sup>10</sup>.
The balance of these two hormones impacts appetite and weight and are all part of set point. Your body wants to stay at a specific weight, so as you lose, it will compensate by releasing more or less of each hormone.
<p class="pro-tip"><strong>Learn more about </strong><a href="/blog/hormones-and-weight-loss">hormones and weight loss</a></p>
Can Set Point Affect Your Ability to Lose Weight and Keep it Off?
The hormonal and metabolic changes associated with set point can make losing or maintaining weight loss harder. But set point theory is not set in stone. It’s just one aspect of weight loss.
Taking weight loss too far, or losing too much body fat, can impact your hormones and set off a chain reaction that triggers you to regain weight. That said, research (and likely your own experiences) suggests there is much more to weight loss than set point.
While the theory looks at our inner signals, body weight and appetite are equally regulated by external environmental factors<sup>11</sup>. Things like access to fresh foods, time, motivation, and support also impact weight loss.
These environmental predictors are known as the settling point<sup>12</sup>, a counterpoint to set point. Set point is internal, while settling points are external factors that impact body weight and appetite. It is much more likely that a combination of internal and external factors determines your ability to lose weight and keep it off.
In other words, healthy lifestyle changes require more than just cutting calories<sup>13</sup> to maintain a healthy weight. Simply restricting calories without making other healthy changes may work initially, but over time it can backfire.
Can You Change Your Set Point Weight?
Since there’s no science saying that set point is the end all be all for weight loss, you don’t have to accept that your set point weight is fixed. Set point is just one piece of the puzzle to making healthy changes.
If your set point revolves around the body’s physiological adaptations to stress or excessive calorie restriction, then attempting to work with your body instead of against it is a smarter move.
Studies on people who successfully lose weight and keep it off do have similar habits. Certain foods, eating patterns, exercise<sup>14</sup>, and behaviors are common to successful maintainers.
Here are some tips for making lifestyle changes to support weight loss:
Slow and Steady Wins
Moderate, slow weight loss may not sell magazine covers, but it’s what works in the long term. First, changes that invoke gradual weight loss tend to be less stressful to your body. Suddenly cut 1,000 calories out of your diet, and your body will defend itself by slowing metabolic rate.
But possibly more critical, slow weight loss from healthy habits can continue long term versus a crash diet that isn’t sustainable. Weight loss of one to two pounds a week on average is recommended.
Even if you stay at a weight for a few weeks or even months, it doesn’t mean that you can’t lose more. Instead, give your body a chance to adapt and reset after a period of weight loss. Consistency over time is what adds up to long-term results.
Bump Up Fiber and Protein
Fiber<sup>15</sup> and protein can help you maintain a healthy weight by increasing satiety (feeling full), stabilizing blood sugar, and slowing the rate of digestion.
High-fiber foods include:
- Whole grains
- Fruits
- Vegetables
- Beans
- Legumes
- Nuts and seeds
High-protein foods include:
- Poultry
- Fish
- Meat
- Dairy
Consider Tracking Your Food
Logging food, at least temporarily, is associated with successful weight loss. People who self-monitor<sup>16</sup> their food intake by keeping track of what and when they eat tend to be more successful.
Tracking can help you see what foods might be sabotaging your efforts. It also helps identify opportunities for improvement in the future. Plus, tracking food is about more than looking at calories. It can help you become aware of macronutrient percentages, how often you’re eating, how different foods impact your energy levels, and even the overall quality of your food.
Add Resistance Training
All movement is important for weight loss, but adding strength or resistance training to your routine can help you maintain a healthy weight. Strength training<sup>17</sup> helps maintain muscle mass, increasing resting metabolic rate, so you burn more calories at rest.
In addition to the health benefits of resistance training, research shows that resistance training can help control body weight, reduce abdominal fat, and improve insulin sensitivity<sup>18</sup>.
Strive for Progress Over Perfection
Finally, make sure to give yourself some grace when it comes to making healthy changes. Setbacks happen even among the most dedicated. People who successfully maintain a significant amount of weight loss often have momentary lapses, but they also have strategies to help them get back on track.
Set Point in Summary
Set point theory suggests that your body has a preferred range where it is most comfortable and will compensate with hormonal shifts to keep you at that weight.
However, set point is only a theory. While hormonal adaptations do occur, there isn’t any specific research that says you can’t lose weight beyond a particular number. You can make healthy changes to your diet and lifestyle that will support your journey.
Consistent progress over time adds up to long-lasting results. If you feel you’ve reached a point where you can’t lose weight or keep it off, finding support from weight loss apps, supportive online communities, or individual nutrition or exercise professionals can be another way to get extra support.
References
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- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2990627/
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- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4267898/
- https://academic.oup.com/nutritionreviews/article/60/suppl_10/S56/1897583
- https://www.sciencedirect.com/science/article/pii/S0896627303000631
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2990627/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3209643/
- https://pubmed.ncbi.nlm.nih.gov/34074915/
- https://pubmed.ncbi.nlm.nih.gov/28481261/
- https://pubmed.ncbi.nlm.nih.gov/26724486/
- https://pubmed.ncbi.nlm.nih.gov/30801989/
- https://pubmed.ncbi.nlm.nih.gov/19346974/
- https://academic.oup.com/jcem/article/85/7/2463/2852127
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