THE SCIENCE BEHIND
THE STRUGGLE WITH WEIGHT MANAGEMENT
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 bodyweight. We likely know at least one other person who diets and exercises regularly, but for some reason is still defending a higher body weight.
We need to look beyond the simple equation of calories in = calories out.
FACTORS THAT AFFECT BODY WEIGHT
There are a number of factors that affect eating behavior 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 play a role as well. For example, the proliferation of apps, and fast food restaurants rapidly expanding in the places we live make unhealthy foods easily accessible and at relatively low cost.
Behavioural factors are also important. These include our dietary pattern, understanding of nutrition, levels of activity, mood, other emotional factors. Sleep patterns, coping strategies, time and stress management, all play a role as well.
THE ROLE OF THE BRAIN IN weight loss
As you can see in this video, two essential systems regulate our eating behaviour and affect our body weight:
The Hypothalamus Homeostatic System is responsible for regulating eating behavior based on the body’s energy needs.
The Mesolimbic Reward System drives eating behavior based on factors like wanting, liking, or comfort.
SET POINT THEORY
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 keeps coming back regardless of the treatment applied. The natural tendency of the body is to defend a predetermined bodyweight or set point.
weight loss triggers a biological adaptive response that increases hunger, decreases satiety (the feeling of fullness) and reduces metabolism. All of these processes occur in an effort to defend that change in bodyweight; particularly in individuals who have had obesity for a long time. For these individuals, the body will defend the highest bodyweight that was ever achieved. This is why after a period of weight loss we 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’.
Losing weight and keeping it off can be difficult. While some people are able to sustain weight loss with diet and exercise changes alone, the majority of individuals are unable to maintain this weight loss over time.
Learn more about weight management: