The World Health Organization (WHO) has released updated guidelines for defining a healthy diet, focusing specifically on carbohydrates, total fat, and specific types of fat, such as saturated fat and trans fat. The guidance supplements previous recommendations on added sugars, sodium and non-sugar sweeteners. In addition to total fat intake, the following recommendations apply to everyone ages 2 and older:
- Healthy eating patterns —food combinations influenced by availability, affordability, preference, culture, tradition, and other factors—are encouraged by the core principles of adequacy, variety, balance, and moderation.
- Encourage a variety of food groups, and a variety of foods from each food group, to reduce the risk of vitamin and mineral deficiencies and to provide a diverse diet of health-promoting ingredients.
- Carbohydrate intake should make up 40-70% of total caloric intake, mainly from minimally processed whole grains, vegetables, fruits and legumes, which have been found to reduce the risk of all-cause mortality and diet-related non- -Infectious diseases (e.g. diabetes, cardiovascular disease, cancer). They recommend 400 grams of fruits and vegetables (equivalent to about 2 servings each) and 25 grams of fiber per day.
- Saturated fatty acid intake should be reduced to 10% or less of total caloric intake, and trans fat intake should be reduced to 1% of total caloric intake, which is associated with reduced risk of all-cause mortality, reduced cardiovascular disease, and lower LDL levels related. They recommend replacing saturated fatty acids with polyunsaturated fatty acids.
- Total fat intake for adults 20 years and older should account for 30% or less of total caloric intake to prevent unhealthy weight gain, and the type of fat consumed should be dominated by unsaturated fatty acids. This amount is associated with reductions in body weight, body mass index, waist circumference and body fat percentage. They cited evidence showing a dose response, whereby the greater the reduction in fat intake, the greater the weight loss. Reduced fat intake is associated with lower caloric intake, resulting in weight loss. The guidelines also state that people who are able to maintain their weight may be able to consume higher levels of fat than 30%; for example, a person may consume 40% of their calories from fat, but consume less carbohydrates and protein in order to get through Consume the same level of calories to maintain energy balance.
What do some experts say?
Experts disagree with the World Health Organization's guideline of limiting total fat intake to 30% or less of total caloric intake, citing evidence from dozens of long-term cohort studies and randomized trials that show benefits for reducing cancer, Risks of chronic diseases such as diabetes, cardiovascular disease, and weight loss Low-fat diet For example, the PREDIMED trial randomly assigned participants to a Mediterranean diet in which fat intake comprised 39-42% of total calories (mostly from unsaturated fats) or A low-fat diet was found to have a lower risk of cardiovascular disease and type. 2. High-fat diet for diabetic patients. Researchers have also expressed concern that lowering total fat intake may mean increasing carbohydrate intake, especially refined carbohydrates and sugar, which have been shown to increase blood pressure and triglycerides.
The WHO's new recommendation to limit total fat intake to 30% of calories is based on a seriously flawed meta-analysis of weight gain. This ignores decades of research on dietary fat and excludes the traditional Mediterranean diet, which is widely considered a healthy eating pattern based on a large body of evidence. Although other aspects of the WHO dietary recommendations are well supported, it is best to ignore the total fat limit.
The WHO report did not include comprehensive randomized controlled trials, but rather selective studies in which weight change was not the primary outcome and many participants had chronic diseases such as cancer, diabetes and cardiovascular disease and were not considered healthy.
The meta-analysis excluded well-designed studies examining changes in dietary fat and body weight, and many of the included studies provided unequal access to interventions. For example, in many studies, low-fat diet groups received intensive instruction and monitoring of fat loss, while control groups received no advice or monitoring. This makes sense because close dietary guidance and monitoring alone can lead to small weight loss.
Even if the results of the meta-analysis were credible, the difference between the low and high total fat groups was only about two pounds (0.9 kilograms after taking sample size into account), which is not enough to make global dietary recommendations. On the other hand, the type of dietary fat has a significant impact on long-term health and well-being, so the recommendation to emphasize unsaturated fat sources in plants rather than those high in saturated and trans fats is well-founded.
