Question

Explain the source and fate of ketone bodies

Explain why it is easier to gain weight than to lose weight.

Answer 1

1) Ketone bodies are substances produced by the liver which is used as a energy source when glucose is not available. It will get converted into acetyl-CoA that enters the citric acid cycle which is oxidised in the mitochondria for energy. Ketones are always present in the blood and levels get increased in blood during fasting and prolonged exercise .

There are 3 ketone bodies produced by the liver. They are acetoacetate, betahydroxybutyrate and acetone. When the glucose levels are high in blood ,it stores the excess as fats and proteins.When you fast, the glucose levels in your blood decrease. This triggers the body to convert fat back into fatty acids, glucose from glycogen and even starts breaking down amino acids for energy.

2) Weight gaining is easier than weight loss because gaining weight requires no energy , effort or life style changes and you eat in a way which encourages to eat. But losing weight triggers biological mechanism which makes difficult to keep the weight off.

When you consume more sugary and carbohydrates food, instead of get rid of energy body stores it as fats cells. Once fat cells formed inthe body ,it may shrink while dieting or exercise but it cannot completely disapear from your body, which is why it is easier to gain weight again.