What happens if 15% or less of total calories come from fat?

Question

Are there any bad side effects or benefits?

Answer 1

Many heart surgeons recommend that you have no more than 15-17 % of your daily calories coming from fat, some even recommend 12-15%.

The only time that it starts to be an issue is if you continually stay under 15%. Remember that all fats are not bad for you. Omega-6 for example (usually from fish) is excellent for you hair,skin and nails in addition to giving you good heart health.
A teaspoon of olive oil on a salad will actually do your body good.

Your brain also needs fat to work correctly.

What you want to do is to weed out the trans fats (usually in processed foods and saturated fat (from meat and full fat dairy products and rely more on polyunsaturated fats-these are the good fats.

Another side issue for women who get their own body fat content under 10% due to continually dieting or avoiding fats is that they no longer get their period. Their cycles get way out of whack and it can affect their chances of getting pregnant when the time comes.

Staying at 16-19% is a better, safe and healthy level. If you want to go lower you should check with your doctor and have blood tests taken.

Answer 2

for women it can decrease testosterone production by as much as 33%. this would obviously cause a decrease in muscle mass and in increase in the body fat. ingesting fat in the diet doesn't make one fat. and reducing it too low doesn't make losing body fat any easier or faster but the exact opposite. fats are essential nutrients to the normal operation of human biology.

low calorie diets that are low in fat and high in fiber are muscle killers for women and should be avoided at all costs.