It seems like most diet gurus talk about the need to count and restrict calories to lose extra fat weight. This is an idea that I've always had a problem with. Why do we need to count calories and consciously starve ourselves to stay thin when most modern hunter-gatherers are usually ripped and muscular without knowing what a calorie is? (1,2) How do they stay so thin while eating whatever they want? The answer is self-regulation.
The Body can Self-Regulate Calorie IntakeYour brain uses powerful feedback systems to regulate appetite and hunger. These feedback systems allow the brain to maintain very specific body weight and body fat set points (I'll delve into these set points in a later post). (3) These feedback systems are designed to ensure that you are getting enough calories and micro-nutrients from the foods that you eat to supply your cells with energy and support your daily physical activities.
There are four main hunger/appetite feedback systems. (4)
- Stress-Leptin Feedback (which makes you hungry when our actual weight drops below a given set point)
- Glucose (blood sugar) Feedback (which makes us hungry when our glucose level drops below a given set point)
- Ghrelin Feedback (which makes us hungry before meals)
- Empty-Stomach Feedback (which makes us hungry when our stomach is empty)
All of these feedback systems have to be satisfied for your hunger and appetite to be satisfied. If a person is healthy, then these feedback systems easily maintain a healthy body weight.
When Hunger Feedback Systems BreakWith a few exceptions (e.g., drinking alcohol, consuming sugar), being overweight often has very little to do with a lack of willpower. Since calories support weight, (5) if you are overweight, then you are overeating; if you are overeating, then one or more of these hunger/appetite feedback systems are likely malfunctioning.
For instance, the hormone leptin tells the brain how much energy is stored in fat cells and when enough food has been eaten. If something interferes with your brain's sensitivity to leptin, then it cannot know exactly how much body fat you have, or when your stomach indicates that you are full. This can lead to overeating.