Nutrition Nutrition Body Weight and Energy Balance Weight is determined by the body's energy balance - if our energy intake and output are equal, our weight is stable. We gain weight if intake exceeds output and lose it if output exceeds intake.
Weight tends to remain stable over the long term and people seem to have a homeostatic set point.
In the 1940s, it was discovered that a region in the lateral hypothalamus triggers the desire for food, called a feeding center. A nutrient is any ingested chemical that is used for growth, repair, or maintenance of the body. Nutrients needed in comparatively large quantities are called macronutrients, including water, proteins, carbohydrates, and lipids. Nutrients needed in comparatively small quantities are called micronutrients, including the vitamins and minerals. Essential nutrients are those that must be included in the diet and cannot be synthesized by the body.