To achieve and maintain a healthy weight in the long term requires that we learn to understand the processes that make us want to eat. Scientists separate appetite and hunger as follows:
- Appetite is a learned experience that relates to our desire for certain types of food and eating experiences. It is responsible for selecting both the quality and balance of the food we eat.
- Hunger, by contrast, is the craving for food associated with sensations such as "hunger pains", a gnawing feeling in the stomach, restlessness, or light headed feelings.
Physiologically this is affected by a number of factors:
- When blood glucose concentrations are lowered, hunger develops.
- When amino acid concentrations in the blood decrease, hunger increases.
- When we're exposed to cold weather, we are stimulated to eat more.
So how do we know when to stop eating? Fortunately, we have nerves in the upper gastrointestinal tract that produce signals to stop eating when the abdominal cavity expands. However, we often eat too much before the signal takes effect - thus it's entirely possible to overeat if we eat quickly, or are eating calorie rich foods. Tactics to avert this include drinking water before a meal, or having soup as a starter.
To avoid wanting to eat again too quickly, think about what you eat - sugary foods will soon empty from the stomach leaving you hungry again, while a protein dense meal will be the most satisfying.
The overall solution is therefore to eat nutritionally balanced meals every two to three hours. Eating small amounts of food throughout the day stops you from getting over-hungry and pigging out, and reduces cravings for high calorie snacks.