A severely low-fat diet can result in poor vitamin absorption, depression, an increased risk of cancer, high cholesterol, heart disease and increased weight gain, according to Registered Dietitian Sarah Haan for SparkPeople. Low-fat diets can also lead to a general nutritional imbalance with more carbs and protein being consumed, increasing the likelihood of developing Type 2 diabetes or osteoporosis.
Fats play a key role in the absorption of vitamins A, D, E and K, which play a vital role in bodily functions such as growth, cell repair and blood clotting, notes Haan. While the 1990s saw the popularity of low-fat diets rise, companies have responded by substituting sugar for fat to maintain flavor. Fat increases feelings of satiation, allowing more time to pass between meals and snacks.
Meats high in fat, dairy products, transfats and saturated fats are unhealthy. However, healthy monounsaturated fats high in omega-3 are an important part of any diet. They can be found in avocados, salmon, tuna and nuts. While total fat intake is dependent on weight and lifestyle, the USDA recommends that calories from fat make up 20 to 35 percent of daily caloric intake, with saturated fats comprising less than 10 percent of that total, according to Healthguide. Research has drawn a link between omega-3s and cognitive function and emotional health.