We know that when we eat more fat than we need we get fatter. But some people eat fatty foods and stay thin, or at least don't become overweight. This may be due to their physical activity level. Some of it is determined by the way their body metabolizes fuel, or can be influenced by the other foods they eat. In most cases, even if they don't get heavier, people who eat high fat foods are building a foundation for eventual heart disease.
Some fat is present in nearly all foods.
Margarine, salad dressings, mayonnaise, nuts, seeds and avocados are very high in fat. When we consume high fat foods, we are adding more to our system than we usually need for a healthy life. Most Americans also consume more protein than they need, more calcium than can be absorbed, and not enough of the foods that provide basic vitamins and minerals. We aren't very good choosers when it comes to eating. The difference between living a long and full life and being ill or disabled is most often determined by the lifestyle choices we make.