The Science Behind Weight Management

Why managing your weight can be a struggle

What determines body weight? We used to think that body weight was determined purely by how much a person eats versus how much energy they burn.

It is true that calorie consumption and energy expenditure do matter but it is an overly simplistic understanding of the factors that influence body weight. We all know somebody who can eat whatever they want and never exercise, while still maintaining a lower body weight. We likely know at least one other person who diets and exercises regularly, but for some reason is still defending a higher body weight.

'calories in' does not equal 'calories out'.

We need to look beyond the simple equation of calories in = calories out.

Many factors affect appetite and body weight

There are a number of factors that affect eating behaviour and body weight. Some of these are modifiable and others are not.

Genetically speaking, a number of genes make us more vulnerable to weight gain than others.

Social, environmental and cultural factors affect body weight as well. For example, family, ethnicity and socioeconomic status all have implications that will determine our body weight.

Behavioural factors are also important. These include our dietary pattern, understanding of nutrition, levels of activity, mood, other emotional factors. Sleep patterns, and stress levels are important to consider also.

Hunger and food cravings happen in the brain

Two essential systems regulate our eating behaviour and affect our body weight:

Hypothalamus Homeostatic System

The Hypothalamus Homeostatic System is responsible for regulating eating behaviour based on the body’s energy needs.

Mesolimbic Reward System

The Mesolimbic Reward System drives eating behaviour based on factors like wanting, liking, or comfort.

Set Point Theory
A phenomenon called the “Set Point Theory” explains why we struggle to lose weight and keep it off

A review of 14 studies of calorie-restricting diets found that weight regain is common after weight loss, with up to 66% of dieters regaining more weight than they lost on their diets.

Obesity is a medically recognized, chronic condition that can keep coming back regardless of the treatment applied. The natural tendency of the body is to defend a predetermined body weight or set point.

Weight loss triggers biological adaptive responses that increase hunger.

These responses occur in an effort to defend against that change in body weight; particularly in obese patients. This is why after a period of weight loss we can so often see the weight come back.

Regardless of diet, exercise, medication or surgical intervention, weight regain is always lurking in the background. A chronic disease that is difficult to treat, obesity requires a long-term treatment plan that extends beyond simple ‘will power’.

Talking to your doctor

Obesity is a medically recognized, chronic condition that requires long-term treatment and support. It is important to speak to a doctor about the options that may be right for you. While talking about weight management can be difficult, doctors are there to help.