What is an “Ultra” Low-Fat Diet?
An ultra low-fat, or very low-fat diet, is a diet that contains 10% or less calories from fat. It also tends to be low in protein (10%) and very high in carbs (80%).
Ultra low-fat diets are mostly plant-based. They limit the intake of animal products, such as eggs, meat and full-fat dairy (6).
They also tend to limit high-fat plant foods that are generally perceived as healthy, including extra virgin olive oil, nuts and avocados.
This can be problematic, because fat serves several important functions in the body.
It is a major source of calories, helps build cell membranes and hormones, and helps the body absorb fat-soluble vitamins like vitamins A, D, E and K.
Additionally, fat makes food taste good. A diet that is very low in fat is not as pleasurable as a diet that is moderate or high in fat.
All that being said, studies show that an ultra low-fat diet can have very impressive benefits against several serious diseases.
Why Do Ultra Low-Fat Diets Work?
Exactly how or why ultra low-fat diets improve health is not very well understood.
Some argue that the blood pressure lowering effects may not even be directly linked to eating a low-fat diet. The rice diet, for example, was extremely low in sodium.
Additionally, the diet was highly monotonous and bland, with a low “food reward” value. This may have caused the participants to unintentionally reduce their calorie intake.
Cutting calories tends to have major benefits for both weight and metabolic health, no matter whether you are cutting carbs or fat.
Despite being high in carbs, ultra low-fat diets are also able to improve insulin sensitivity and blood sugar control in some people.
Health Effects of Ultra Low-Fat Diets
Ultra low-fat diets have been studied against several serious diseases, including heart disease, diabetes, obesity and multiple sclerosis.
Here is a summary of the findings.
Studies have shown that the ultra low-fat diet can improve several important risk factors for heart disease:
- High blood pressure (8, 9, 10).
- High blood cholesterol (8, 10, 11, 12).
- High C-reactive protein, a marker for inflammation (8, 13).
One study of 198 patients with established heart disease found particularly striking effects. Out of the 177 patients who followed the diet, only 1 patient experienced a cardiac event (stroke) (14).
However, 13 of 21 (62%) of patients who didn’t follow the diet experienced a cardiac event.