Contrary to popular belief, low-fat foods aren’t any healthier or safer to eat than their full-fat versions.
Low-fat diets endorsed by celebrities, dieticians, and even some nutritionists are actually detrimental to your health.
This is because fat is actually an important nutrient that plays a key role in brain health, metabolism, cardiovascular function, and reproductive health.
The Dangers of Low-Fat Foods
1. Sugar Content
Fat is used to enhance the flavor and texture of foods to make them more appealing. Fat-free processed foods compensate for the lack of flavor by using additives that mimic the texture of fat, such as gums, inulin, maltodextrin, polydextrose, starch, and modified food starch (1).
Because fat-free foods contain high levels of sugar and other sweeteners to enhance their taste, consumers are often left feeling satisfied only for a short period of time. This can lead to overeating and unnecessary weight gain.
2. Cardiovascular Problems
Healthy sources of fat, such a fish, vegetables, and nuts help your body absorb fat-soluble vitamins and provide a stable source of energy.
Low-fat food, on the other hand, contains hydrogenated fats which increase your levels of trans fats and damage your heart . Their high sugar content also raises your cholesterol and contributes towards the development of heart disease (3).
In a study published in the Journal of American College of Cardiology, Sylvan Lee Weinberg, MD, MACC, explains the dangers of a low-fat diet : “The low-fat, high-carbohydrate diet… may well have played an unintended role in the current epidemics of obesity, lipid abnormalities, type 2 diabetes, and metabolic syndromes. This diet can no longer be defended by appeal to the authority of prestigious medical organizations.” (4).
The current Dietary Guidelines for Americans recommend a diet containing 20 to 35 percent fat from healthy sources. These sources should contain omega-3 fatty acids, which help protect you from hypertension, cholesterol problems, cognitive decline and heart disease (5,6).
3. Hormonal Imbalance
Cholesterol typically produces 5 different classes of steroid hormones, like progestogens, glucocorticoids, mineralocorticoids, androgens, and oestrogens (8).
Glucocorticoids help produce glycogen, break down fat and protein, and prevent chronic inflammation while Mineralocorticoids regulates kidney function. The other 3 are important sex hormones that play a role in reproduction and sexual expression.
4. Weight Gain
Being fat doesn’t just happen by eating too much fat. There are many other factors that come into play when it comes to weight gain.
The U.K. Mirror reports that a study by Brigham and Women’s Hospital and the Harvard T.H. Chan School of Public Health found low-fat interventions were no more successful than higher-fat interventions in achieving and maintaining weight loss for periods longer than one year (9).
Dr Deirdre Tobias at Bingham’s Division of Preventive Medicine said that “Despite the pervasive dogma that one needs to cut fat from their diet in order to lose weight, the existing scientific evidence does not support low-fat diets over other dietary interventions for long-term weight loss.”
“We need to look beyond the ratios of calories from fat, carbs, and protein to a discussion of healthy eating patterns, whole foods, and portion sizes.”
Another study published in The Lancet Diabetes & Endocrinology analysed 53 studies with a total of 68,128 participants and found that low-carb interventions did more to support weight loss than low-fat interventions did.
Foods high in simple carbs and low in fat are digested more easily than foods high in protein or fat. Because they are easily digested, these foods can cause your blood sugar levels to spike upwards and crash shortly after your meal. When your blood sugar levels aren’t stable, your body begins to crave quick sources of energy go keep it going.
In contrast, eating healthy fat keeps you full and satisfied, so you’re less likely to overeat or crave sugary foods throughout the day. A study published in Obesity magazine in 2010 even found that eating healthy fats can prevent hunger pangs and promote weight loss
5. Mental Health Problems
There are many ways by which eating healthy fats can improve brain function.
Brain cells rely on cholesterol to conduct activities related to memory and learning, neural communication and neurogenesis (the birth of new brain cells) (10).
Cholesterol also allows your skin to manufacture vitamin D, which prevents cognitive decline, dementia and Alzheimer’s.
Moreover, fats help prevent mental health problems, like depression. Studies show that Omega-3 fatty acids (particularly EPA) improve symptoms of depression, anxiety, sleep, lassitude, low libido, and suicidal ideation as effectively as medication (11).