Does the Body have a Set Point Weight?

Whether you’re trying to lose weight, gain weight, or maintain a healthy weight, you may have noticed your body tends to settle around a specific weight over time. This concept is known as the set point weight theory and may explain why some people struggle to maintain changes in body weight.

What is the set point theory?

The set point weight theory is a scientific theory that suggests the human body has a predetermined weight or fat mass range (1). According to this theory, our weight is hardwired into our DNA and our body will aim to keep weight stable or within a specific weight range.

The concept of weight set point was first introduced in 1953, when scientist Gordon C. Kennedy proposed that body fat storage was regulated. This concept was further expanded upon in 1982 when nutritional researchers William Bennett and Joel Gurin used his findings to develop the set point theory.

However, a challenge was made to the set point theory when researchers D. Wirtshafter and J.D. Davis published a paper discussing how lifestyles habits and environments played an important role in the control of our body weight. Their research suggested that our body weight does not have a specific set point, but rather a settling point due to these factors, which are largely within our control (2).

Does a body weight set point exist?

The set point weight theory has long been a topic of debate; however, the overall body of research demonstrates that body weight is caused by a multitude of factors, not a pre-determined set point.

Body weight is determined by a combination of uncontrollable factors, including genetics, height, sex, and age, and controllable factors, including diet, activity level, lifestyle, and environment. While biology may determine the upper and lower limits of body weight, behavioral and environmental factors determine the specific settling point between those limits (3).

Factors that Influence Set Point Weight

Here is a list of the factors that affect your set point weight.

Genetics

Personal genetics are the largest influencing factor of body weight settling point. Not only are some people genetically predisposed to have more lean body mass than others, but research has found large variations in body mass index (BMI) and body composition by ethnic groups (4, 5). Certain individuals can maintain lower body weight on similar diets due to genetic differences in metabolism, appetite regulation, and fat distribution (6).

Height

While height is primarily determined by genetic factors, it plays a role in body weight settling points. Put simply, taller people have more mass than shorter people.

Sex

Biological sex also plays a role in body weight settling point as bone density, muscle mass, and body fat naturally vary between men and women. Men generally have higher bone density and more muscle mass than women, and women naturally carry more body fat than men (7, 8).

Age

While genetics may predetermine a person’s weight range early in life, a person’s settling point weight can be influenced by their age. Not only do adults tend to lose weight as they age, especially through losses in muscle mass, but certain life stages, such as childbirth and menopause, can influence a person’s weight.

Metabolism

Metabolism regulates human body weight as our basal metabolic rate and total daily energy expenditure, along with diet, dictate whether your body is in a calorie deficit, which is required for weight loss, or a calorie surplus, which is required for weight gain.

Moreover, long-term dieting can lead to metabolic adaption; a natural physiological process that reduces energy expenditure below predicted levels in response to weight loss (9). Also known as adaptive thermogenesis, metabolic adaption is a built-in safety mechanism that occurs to maintain biological homeostasis and protect the body from starvation if calorie intake, BMI, or weight drops too low.

Therefore, when you consume fewer calories while dieting, your body will gradually slow down your basal metabolic rate, making it more difficult to lose weight on the same calorie deficit, and will increase hunger signals in the process. This is one of the primary causes of weight loss plateaus.

Hormones

The hunger hormones leptin and ghrelin also play a role in set point theory and body weight settling points (10). Leptin and ghrelin work on a negative feedback loop to control food intake; leptin tells you when you’re full and ghrelin tells you when you’re hungry. These hormones are affected by adipose tissue (body fat) and the size of the individual cells controls body fat set point; as body fat decreases, leptin signals decrease, causing basal metabolic rate to decrease, which can cause body fat to return to the previous set point (11, 12).

Lifestyle Choice

Daily lifestyle habits also play a major role in body weight settling points. Everything from activity to exercise to sleep impacts body weight settling points and, generally speaking, a relaxed, well-slept, and active individual will have a lower body weight set point than a stressed, exhausted, and sedentary individual. Not to mention, lifestyle choices have a big impact on food choices, which is a major factor in body weight regulation.

Dietary Habits

Unsurprisingly, our diet has a huge impact on body weight settling point. Not only does food quantity influence body weight, as eating too much and too little affects weight, but the quality of our food and the macronutrient breakdown of our food choices influence both weight and body composition.

For instance, a diet with a high level of processed foods may lead to overconsumption of calories and cause weight gain in the long term. Moreover, the composition of protein, carbohydrates, and fats in our diet plays a major role in muscle mass, adipose tissue, and weight range.

Environment

Cultural and environmental barriers such as religious practices and the cost and availability of food can also influence body weight settling points.

Can you change your set point weight?

While genetics play a major role in your body weight, your set point is not fixed and, therefore, can be changed. As opposed to a fixed number, body weight operates in a range with healthy upper and lower limits, and the settling point between these limits is determined by controllable behaviors.

Our body weight settling point can be changed through the regular practice of healthy eating habits, calorie and macronutrient intake, exercise, and activity. While diet and exercise are important for weight loss, diet has a greater impact as it helps to directly manage calorie intake to create a calorie deficit, which is the sole requirement for weight loss.

That being said, exercise, specifically resistance training, is an effective tool to support weight loss, given it helps to build muscle mass, which is one of the key components in metabolism. Research has shown that individuals with increased muscle mass have a higher resting metabolic rate (RMR) (13). Moreover, resistance training is more likely to enhance fat loss than cardio, as resistance training will increase the energy you expend when you are not working out (14).

Tips to Alter or Improve Your Settling Point Weight

Here are important tips to change your body’s set point weight:

• Have realistic expectations. Unfortunately, many people begin a weight loss journey with unrealistic expectations, get frustrated, and give up. While there are many reasons you may not be losing weight, it’s important to understand that weight loss takes time and it’s normal to experience weight loss plateaus in the process.
• Be open to learning. Understanding the science-based rationale of the dietary changes required for weight loss can increase adherence and serve as a motivator. Moreover, learning the difference between weight loss and fat loss fat can help to accurately set expectations in the process.
• Set goals. Creating short-term and long-term personalized goals is very helpful for changing body weight and body composition. Long-term goals highlight a specific desired result, such as losing 20 pounds or reducing body fat to 20%, while short-term goals communicate a result you want quickly, such as meal prepping for the week or going to the gym after work.
• Seek intrinsic and extrinsic motivators. Research has shown that intrinsic and extrinsic factors are important for keeping weight loss subjects on track (15). While intrinsic factors, such as self-esteem, are primary drivers, extrinsic factors, such as social standing and career opportunities, also play an important role.
• Prepare yourself for challenges. Hurdles are to be expected in a weight loss journey and challenges – internal and external – can derail you if you’re not prepared. Everything from the struggle of everyday life to larger life events, such as holidays, breakups, and family troubles, must be endured during the weight loss process.
• Ask for support. Interactions with supportive friends, family, colleagues, or health professionals are key during the weight loss process. Not only can they hold you accountable to your goals but they can help you weather the storm when challenges arrive.

FAQs

The Bottom Line

Set point weight theory suggests that the human body has a predetermined weight or fat mass range. Our set point weight is influenced by our genetics, height, sex, age, metabolism, hormones, lifestyle choices, and dietary habits. Contrary to popular belief, our set point weight is not fixed, rather, it is seen as a settling point between upper and lower ranges, which can be influenced by diet and lifestyle changes.