Carbohydrate-Insulin Model vs. Energy Balance Model

Sigma Nutrition Radio

Episode 429

With Kevin Hall and Stephan Guyenet

Available: HERE

Summary of Content From Sigma

The pathogenesis of obesity is clearly complex. And the need to have a comprehensive model to explain this pathogenesis is important.

One such model, termed the Energy Balance Model, has largely been the consensus paradigm of obesity scientists to this point. Specifically, a recently published paper in the American Journal of Clinical Nutrition by Dr. Kevin Hall and his colleagues outlined the various nuances of the model, as well as common misconceptions about the model.

However, there are others who propose that this is not the correct model of obesity, but rather that obesity pathogenesis can be better explained by a model called the Carbohydrate-Insulin Model (CIM) of obesity.

While this model has been proposed in various forms over the past couple of decades, the most recently published revision/update of this model was that put forward by Dr. David Ludwig and colleagues, in a Perspective published, also in the AJCN, in December of 2021.

In this episode, Dr. Kevin Hall (lead author of the paper mentioned above) and Dr. Stephan Guyenet are on the podcast to discuss the debate surrounding these two models. Specifically, the discussion will focus in on the Hall et al. (2022) and Ludwig et al. (2021) papers, as well as previous work leading up to both.

What did I learn from this information?

• Carb-insulin model (CIM) of obesity initially very simplistic.

• New model much more complex but still focuses on insulin and high glycemic load carbs having significant effect.

• Energy balance model, brain plays key role in weight.

• Expression of genetics impact brain’s function.

• Interactions with food environment impact brains ability regulate weight

• Goes beyond simple hedonic factors.

• Hedonic circuits in brain also feedback to homeostatic regions to control food intake.

• We need to understand gene environment interactions to predict susceptibility to obesity.

• Energy balance model is not the same as principle of energy balance.

• This model does not say that calories are the only thing that matter, common myth or claim by some people.

• Macronutrient composition of the diet has some very small effect on energy balance and adiposity, total energy intake has significant effect.

• 180 years ago patient developed extreme obesity in very short space of time, autopsy found tumour in hypothalamus, initial evidence for brain control of body weight.

• CIM suggests that external factors such as high glycaemia can override brains ability to regulate body weight.

• Both models recognise impact of food environment on increasing levels of obesity in society.

• Food palatability strongly associated with amount of food intake during a meal.

• However, impact on obesity not so clear.

• Food reward causes us to select refined high calorie foods.

• Wide range of food decisions not under conscious control.

• Only partially aware of habits, only fully aware when actively reflecting.

How Will This Learning Improve My Practice?

Having a clear understanding of the prevailing theories within my field of practice will be important to ensure my interventions are evidence based and best placed to help my clients. This information has helped me understand some of the complex issues within the field of obesity research and recognise how they fit into research and day to day practice.