Diet Planning and Weight Loss

What are the three primary fuel sources used by the body?

Carbohydrates (stored as glycogen), fats, and proteins.

How are carbohydrates stored in the body, and why does this affect "water weight"?

Carbohydrates are stored as glycogen in the liver and muscles, and each gram of glycogen is stored with 3-4 grams of water. When glycogen is depleted, the water is also lost.

Under what circumstances does the body use protein as a fuel source?

Protein is used as fuel during prolonged starvation or when carbohydrate stores are depleted; however, its primary role is for tissue repair and maintenance.

What is the primary role of fats as a fuel source?

Fats provide a concentrated source of energy (9 kcal/g) and are primarily used during low-intensity exercise and at rest.

What role does insulin play in nutrient metabolism?

Insulin regulates blood glucose by promoting the uptake of glucose into cells, stimulating glycogen synthesis, and encouraging fat storage when there is excess energy.

How does prolonged calorie restriction (starvation) affect basal metabolic rate (BMR)?

Starvation lowers BMR by 10-30% as the body enters "starvation mode" to conserve energy, reducing overall energy expenditure.

What is refeeding syndrome and why is it dangerous?

Refeeding syndrome is a metabolic disturbance that occurs when nutrition is reintroduced too quickly after starvation, leading to severe electrolyte imbalances (especially hypophosphatemia) that can cause life-threatening complications.