Criticism of the study: No lower mortality due to more fat and fewer carbohydrates
Recently, an international study concluded that a diet high in carbohydrates and low in fat increased the risk of death. The authors advocated revising existing dietary recommendations. German scientists disagree with the conclusions of the study.
Less carbohydrates and more fat
The dispute over whether less fat or fewer carbohydrates is suitable for losing weight quickly has been going on for years. Scientific studies have shown time and again that low-carb diets can help you slim down more quickly, but it is controversial whether it is also healthy to reduce bread, pasta, rice and the like on the menu and to reduce fat or proteins to put. A recent international study came to the conclusion that this is definitely recommended for health reasons. German scientists are now criticizing this conclusion.
Researchers call for changes in dietary recommendations
A recently published study, which examined the influence of carbohydrates, fat and protein in the diet on the risk of disease and mortality in 18 countries, concludes that too many carbohydrates in the daily diet increase mortality.
The study found that more fat, including saturated fat, was not only not harmful, it also reduced mortality and the risk of stroke.
The authors of the global nutritional study PURE (Prospective Urban Rural Epidemiology) call for the global nutritional recommendations regarding fat and carbohydrates to be rewritten.
Scientists from the University of Hohenheim in Stuttgart criticize these conclusions. The university's methodology and results did not allow such far-reaching conclusions to be drawn at all.
No causal relationships
According to the study, mortality increases with the intake of carbohydrates; for fat, the researchers observed an inverse relationship: with an increasing proportion of the food energy from fat, mortality decreases.
"But even if lower mortality is associated with higher fat consumption or lower consumption of carbohydrates, no causal relationships between these observations can be established with this method," says nutritionist Prof. Dr. Konrad Biesalski to consider.
Together with the tropical expert Prof. Regina Birner and the nutrition scientist Prof. Jan Frank, President of the Society of Nutrition and Food Science (SNFS), he explains that there is a direct causal relationship between the total amount of carbohydrates and fat in the diet and the Mortality is not given.
"The decisive factor is rather the quality of the diet, ie the content of important vitamins and minerals."
The supply of micronutrients is crucial - and the proportion of carbohydrates and saturated fats in the diet is just an indicator.
“With increasing poverty, the proportion of carbohydrates increases significantly, and that of foods of animal origin, especially meat and meat products, decreases. Because starchy products like rice, corn, wheat, potatoes or cassava are inexpensive and satiating, ”explains Prof. Birner.
However, these are a bad source with regard to the supply of essential micronutrients, and the supply of iron and zinc, for example, has an impact on mortality.
“An insufficient supply of micronutrients, i.e. minerals and vitamins, increases the risk of illness and, inevitably, the risk of mortality. If the quality is neglected, considering the quantity of macronutrients in the diet is easily misleading, ”says Prof. Jan Frank.
"A high-fat, low-carbohydrate diet can be just as poor in quality as a low-fat, high-carbohydrate diet."
Poor and rich nations differ in carbohydrates
"When it comes to carbohydrate consumption in poor countries, we mainly speak of rice, corn and wheat," summarizes Prof. Biesalski. "The greater their share of the diet, the lower the quality of food and the higher the mortality rate."
In rich nations, however, the carbohydrate intake is in the range of 45 to 55 percent.
“Here too much carbohydrates means above all too much sugar and sugary foods. Reducing this is certainly not a mistake and possibly also health-promoting. "
"A sensible nutritional recommendation should take into account the quality of the carbohydrates (simple sugar vs. complex carbohydrates) and the causes of high carbohydrate consumption (especially poor food in poor countries)," the German experts write in a comment.
"In view of the prevailing lack of high-quality food and a small selection of foods, it is simply not realistic to recommend the population of poor countries to reduce carbohydrate intake and increase fat intake," it continues. (ad)