Eating too much fat can increase your risk for a number of health threats. For starters, eating a lot of fat can make you fat. Fat contains 9 calories per gram. That means fat packs more than twice as many calories as carbohydrates and protein, which both have 4 calories per gram. Your body needs fat to survive, but it's wise to eat this important nutrient in moderation.
Too much of certain types of fat can lead to other health problems. A diet rich in saturated fat (fatty cuts of meat and dairy foods are top sources) can raise cholesterol levels in the blood. That increases the risk for heart disease. Likewise, the trans fats found in some fried foods, packaged snacks and stick margarine (among other foods) raise cholesterol, too. If eating too much fat causes you to become overweight or obese, this raises your risk of endometrial, breast, prostate and colorectal cancers.