Weight is a fascinating thing. Overweight people struggle with dieting and exercise, constantly cycling between losing and regaining weight, yet never seem to achieve their desired results. On the other hand, some people remain skinny despite overeating, unable to gain weight no matter how hard they try. Both groups seem to follow the "calories in, calories out" principle, but their results are vastly different. This discrepancy might be due to the body's "set point."

The Body's Set Point: A Built-In Weight Regulator

More than 40 years ago, scientists discovered that, under natural conditions, a person's weight tends to stay within a stable range, often referred to as the "set point." If weight deviates from this range, the body employs various compensatory mechanisms to bring it back to normal.

When trying to lose weight, if it drops below the set point, the body will make you eat more and burn less to regain the lost weight. Conversely, if you gain weight beyond your set point, the body increases energy expenditure and suppresses appetite to return to its original state. In simple terms: losing weight is tough, and so is gaining weight.

How Does the Body Maintain a Stable Weight?

Control Your Appetite? It's Not That Simple

You might have noticed that some skinny friends seem to lose their appetite easily, finding eating a chore, while others have an insatiable hunger. The control center for appetite is located in the hypothalamus, which regulates your hunger and satiety through two types of hormones: those related to "hunger" and those related to "fullness."

During weight loss, as your weight falls below the set point, your body perceives the reduced calorie intake as an emergency, leading to an increase in hunger hormones, compelling you to eat. Conversely, when you gain weight, the body senses that calorie intake is sufficient and signals that eating more could cause discomfort.

Exercise More? Meet "Energy Compensation"

If controlling appetite is challenging, what about relying on exercise? Despite spending hours in the gym or following intense workout routines, many find their weight unchanged. The body has an "energy compensation" mechanism: when it detects increased calorie expenditure from exercise, it reduces basal metabolic energy consumption to compensate for the lost calories.

Last year, a study published in Cell's sub-journal revealed that lean individuals have a smaller energy compensation mechanism, while overweight people have a more significant one. Essentially, the more you exercise to create a calorie deficit, the more your body tries to offset it.

Rapid Weight Changes? Basal Metabolic Rate Adjustment

Extreme dieting or overeating can lead to quick weight loss or gain, but the body will adjust its basal metabolic rate to restore the set point. During prolonged calorie restriction, the body enters "energy-saving mode," reducing metabolism to conserve energy and prevent further weight loss.

This often results in a "plateau" during dieting, accompanied by fatigue, irritability, and other symptoms. Conversely, when overeating, the body increases energy expenditure to burn off the excess calories.

The Final Revenge of the Set Point: Rebound Effect

Whether you've lost or gained weight quickly, your body will strive to return to its set point, sometimes overshooting it. This "rebound effect" makes maintaining weight loss or gain challenging. Even after resuming a normal diet, your body may stay in low-energy mode, increasing appetite hormones to regain the lost weight.

Is It Hopeless?

Not at all. Many people have successfully changed their weight long-term. The set point can shift slowly over time with sustainable lifestyle changes. Instead of extreme measures, focus on gradual changes to find a new balance with your body.

Expert Tips

Rapid weight loss often results in muscle and water loss rather than fat. To maintain metabolic rate, protect your muscle mass by increasing protein intake and incorporating regular resistance training. Avoid severe calorie restriction, as it can lead to rapid fat regain and muscle loss.

By understanding and working with your body's natural mechanisms, achieving and maintaining a healthy weight is possible.