Psyc417 Body Weight Management
Last updated: 1/9/2025
Questions
Notes
The goal of this lecture is to teach about what leads to obesity and how people tend to lose weight
Drastic weight change is difficult. When you go on a diet to lose weight, you will lose weight quickly first and then you will stop losing as much weight. You will start to be hungrier, you will decrease your BMR.
A recent study compared the outcome of Western diet and microbiome enhancer diet in humans. The gut microbiome harvest energy from foods to produce short chain fatty acids.
Your diet and microbiome determine somethings about your gut. Some bacteria make your gut leaky (and make it easy to absorb macronutrients) and the same bacteria cause inflammation.
Microbiome enhancer diet increased post-meal GLP-1 llevels and calories in the stool (they don't absorb all calories and are also satiated faster).
In the western diet, 32.1 calories were excreted while in the microbiome diet 73 calories were excreted from the stool.
If the diet is adhered closely then the efficacy of weight loss is about the same for all diets which means that the best diet is the one that you can follow for the longest.
Obesity epidemic
Some causes of obesity are food additive chemicals, changes in lifestyle,
Three evolutionary causes for obesity:
- Thrifty genes - we have genes that enable us to survive through periods of famine. we store energy and wait for later.
- Drift genes - some mutations have occured that cause some peolpe to be obesity prone and obesity resistant.
- Obesity is a maladaptive by-product of positive selection on some other trait.
Gelesis100 (aka Plenity) is a pill that you take with 200 mL of water. If you take 3 before a meal then you will eat less because you will be volumetrically satiated.
More women get bariatric surgery than men
Bariatric surgery causes a lot of weight loss, but there are also some cons of its such as alcohol use disorder and self-harm.
Exercise can prevent obesity but some humans are responders and nonresponders. People that don't respond to weight loss usually have compensatory behavior. They usually overestimate the amount of calories they burn and eat more.
When people lose weight they increase their hunger but also decrease their metabolism which can cause weight gain. It is definitely hard to lose weight and maintain the weight loss. Slower weight loss is better for long-term outcome.
For the participants of the biggest loser there is no correlation between energy intake and weight loss maintained. The more physical activity per day the more weight they keep off.
Fasting decreases inflammation and increases insulin sensitivity. It also increases autophagy.