Why Eating Less and Moving More is Not the Solution for Obesity

I'm Dr. Carl Magnus Brodin, a medical gastroenterologist physician at the obesity medicine and bariatric surgery clinic GB Obesitas in southern Sweden.

In the next five minutes, I'm going to give you some insights about the set points for bodyweight mechanisms.

How can we lower the set points of bodyweight with treatments?

What works and what does not?

OK, let's dive into this.

First, let's do a short summary of how our body normally defends itself against diet-induced weight loss.

After weight loss, a patient will experience the following.

You are constantly increasingly hungry and craving foods.

And once you do eat, the feeling of fullness only lasts a half hour or so, then you go back to being hungry again.

What's happened now is that the body has started to biologically defend itself against the caloric deficit.

You're hungrier because your body has produced powerful starvation hormones, such as ghrelin, and less full because your satiety hormones, such as leptin, are down.

You even burn less when you exercise.

The organs that decide your body weight long-term are a number of neurons in your hypothalamus that receive and process all the feedbacks from the body, including the starvation and satiety hormones we just mentioned.

The sum of activity two and interactions between these neurons decides our body weight long-term.

This is the so-called set point for body weight or weight thermostat, if you so will.

So in order to effectively treat a high BMI with weight loss and keep that weight off long-term, it is essential to lower the body's weight thermostat setting.

Conventional weight loss diets do not do this.

But if weight loss diets don't lower our set point for body weight, then what does?

Modern anti-obesity medications will be effective in lowering the set point for body weight if and when a patient A, tolerates the medication side effects, and B, response to dose escalation.

Typical initial side effects are gastrointestinal, including nausea, but will often fade over time.

One treatment option is tablets containing the combination of bupropion and naltrexone.

In a responder patient, you can lose 10% to 15% of your total body weight using this.

Another modern option is the group of GLP-1 receptor agonists, such as liraglutide or semaglutide, taken as subcutaneous injections.

Here, a responder may experience around 15% total weight loss.

Terecepatide is a combination drug affecting both the GLP-1 and GIP receptors.

Here, weight loss around 20% total weight loss or more is described in studies.

All treatment effects are reversible in the sense that if you stop the medication, the set points for body weight will most likely go back up to its original level.

Treatment thresholds here are in general BMI of at least 30 or a BMI of 27 plus other obesity related conditions.

Modern bariatric surgeries are in general the most effective in lowering the body weight set point in the brain.

The most common surgeries are the sleeve gastrectomy and the gastric bypass, but other methods include the mini-gastric bypass, the SASE, duodenal switch, and more.

Here a patient loses between 20 and 45% of total body weight depending on response and surgery type.

Treatment thresholds here may vary slightly in different regions, but in general, they are a BMI of at least 35 to 40, alternatively a BMI of at least 30 to 35, plus other obesity-related conditions.

So does this mean that diet and exercise doesn't matter anymore?

No.

For set-point lowering treatments to be effective long-term, you must incorporate healthy behaviors in parallel.

So it's modern medications or surgery plus healthy behaviors, not either or.

I'm Dr. Carl-Magnus Brodin for 5 Minutes CPD.

Thanks for watching.

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