Introduction

Some people regain weight after dieting, while others maintain weight easily. One explanation for this phenomenon is the set-point theory. According to this theory, weight regulation is automatic until it reaches what is called a “weight thermostat”. Your body makes changes to the weight you are trying to reach by increasing appetite, kicking in metabolism, and using energy.

What is set-point theory?

The set-point theory argues that each person has a biological weight range that has been predetermined. When the weight fluctuates over this range, biological factors kick in to reverse the changes.

The first theory came from the 1970s from research on metabolism and appetite. Researchers compared the human body to a thermostat. “If you gain weight, your body increases energy expenditure and reduces appetite. If you lose weight, your body lowers energy expenditure and increases hunger.” Your body is wired to defend its set point.

How the Body Defends Its Set Point

The brain, hormones, and fat cells work together to coordinate the system responsible for your body weight.

1. The Role of the Hypothalamus

The hypothalamus is responsible for keeping the brain and the body in sync and maintaining the balance between hunger and energy. It receives feedback signals and hormones and balances energy expenditure and food intake.

3. Hormonal Signals

The most important are:

• Leptin. Secreted by fat cells, it tells the brain that energy stores are sufficient, and hunger should be turned off.

• Ghrelin. The “hunger hormone” secreted during empty stomach periods to stimulate appetite.

• Insulin. It regulates blood sugar and fat storage. When it is persistently high, it causes appetite dysregulation.

When body fat is lost, the body is wired to regain it. This is when leptin levels drop and ghrelin levels rise, leading to stronger hunger signals.

Evidence That The Set-Point Theory Is Correct

• Some evidence in favour of the set-point theory comes from studies about diets. When a dieter loses weight, even a considerable amount, and keeps calorie intake even lower, the dieter will eventually gain the weight back quickly. This has been attributed to the dieter’s metabolism rapidly adapting to a lower calorie intake.

• Similar to the studies regarding diets, the classic Minnesota Starvation Experiment (1944) showed that the participants’ metabolisms eventually slowed to a dramatic extent during calorie restrictions of the experiment, where it not only remained suppressed even after the experiment, but the weight regained was suppressed as well.

• Over the course of several weeks, if a person is able to eat as much as they desire, their metabolism will increase during that phase and their body will be able to burn off the excess calories. This only last until eating returns to normal.

This indicates that the body defends a certain range of fat storage and is able to do so both upwards and downwards.

Criticisms and the “Settling Point” Model

Even though the Set-Point Theory clarifies a substantial amount of phenomena regarding weight- regulation, critics are still able to point certain flaws in it as well. The critics suggest that the Set-Point Theory does not take environment and behaviour into account, which play a huge part.

In contrast to the Set-Point Point Theory, the “settling point” model suggests that the body weight at a certain point is a dynamic regulation in the body. That means it fluctuates based on an interrelation of facets, be it biological, environmental, or lifestyle related.

For example, if someone is allowed to overeat and be inactive, or if they are kept in a stressful environment, the body’s weight can be “reset” to a higher, and in some cases, unhealthy weight where it will stay as the new “normal”.

It is not uncommon for westernised, modernized countries to gain excess weight due to high calorie intake and low energy expenditure or activity. It is likely people have raised their Set Point over the years.

Changing Your Set Point

Although each person may have a genetic predisposition that forms the basis for bodily defenses, long term bodily weight regulations can be modified through lifestyle approaches.

• Here are a few approaches that may lower your set point over time:

• Avoid crash dieting, as this creates strong metabolic defenses. Instead, practice consistent moderate caloric deficits.

• Incorporate lean mass building exercises. This increases your resting metabolism.

• Include a sufficient amount of protein and fiber. This helps to sustain your blood sugar and will keep you full longer.

• Manage your stress and get enough quality sleep. Poor sleeping habits and excess stress will lead to increased fat gain due to elevated cortisol levels. Sustaining weight loss for 1 to 2 years would allow your body to adapt to long-term maintenance.

Conclusion

Your body resists changes, and set point theory articulates this concept well. But your body is not a prison, and with the right, consistent, balanced practices, the weight your body “settles” at can be influenced. No, your changes don’t have to be extreme, they just have to be gradual and sustainable in the right fusion of nutrition, exercise, and lifestyle.