Do Carbs Make You Fat?

There is a common misconception that eating fat does not make you fat and that only carbohydrates make you fat.

This is completely wrong. You can get fat from eating fat.

If you're sitting around all day eating carbs, the excess carbs do get stored as fat. I don't deny that. However, if you're sitting around all day eating fat (e.g. butter, coconut oil, etc), the excess fat gets stored as fat as well.

In fact, the study below shows that excess fat in your diet is stored as fat with greater efficiency than excess carbohydrates:

We overfed isoenergetic amounts (50% above energy requirements) of fat and carbohydrate (for 14 d each) to nine lean and seven obese men. A whole-room calorimeter was used to measure energy expenditure and nutrient oxidation on days 0, 1, 7, and 14 of each overfeeding period. From energy and nutrient balances (intake-expenditure) we estimated the amount and composition of energy stored. Carbohydrate overfeeding produced progressive increases in carbohydrate oxidation and total energy expenditure resulting in 75-85% of excess energy being stored. Alternatively, fat overfeeding had minimal effects on fat oxidation and total energy expenditure, leading to storage of 90-95% of excess energy. Excess dietary fat leads to greater fat accumulation than does excess dietary carbohydrate, and the difference was greatest early in the overfeeding period.

http://ajcn.nutrition.org/content/62/1/19.abstract

Carbs at Night Make You Fat?

There is a misconception out there that eating carbs at night will make you fat because at night the body typically burns fat, but if you consume carbs, the body will stop burning fat and start burning carbs instead.

The truth is that it doesn't matter whether you eat carbs, protein, or fat. You gain weight if the calories you consume is more than the amount you burn.

Most people burn approximately 2000 calories per day without exercise. For the sake of this example, let's say this equates to roughly 1000 calories burnt at night while you sleep.

If you eat 900 calories before you sleep, you will burn all the 900 calories eaten and then burn 100 calories of stored fat, which will result in weight loss. It doesn't matter whether you ear carbs or fats as they will both be burnt.

However, if you eat 1100 calories before bed, you will gain weight as there is a surplus of 100 calories. If you ate carbs before bed, this 100 calorie surplus will be converted to fat and stored. If you ate fats before bed, the 100 surplus calories of fats will be stored as fat.