Health assessment of carbohydrates, fats and proteins in food

The BfRshort forGerman Federal Institute for Risk Assessment carries out health risk assessments on specific issues relating to carbohydrates, fats and proteins - also known as macronutrients. These substances provide the organism with energy and are used to build the body's own structures.

Carbohydrates, together with fat, are used primarily to meet the energy needs of humans. They are found in food as sugars (monosaccharides and disaccharides) or starches (polysaccharides).

Adults should get at least 50% of their daily energy intake in the form of carbohydrates. The German Nutrition Society recommends eating foods that are high in starch and fibre, such as grains (and grain products), vegetables, fruit and legumes, as these foods also contain vitamins, minerals and trace elements and have a high satiety value due to their high fibre content.

In contrast, the consumption of beverages sweetened with sugar should be limited, since a high consumption of these foods increases the risk of obesity and secondary diseases such as type 2 diabetes mellitus, but also caries.

The data from the National Consumption Study II of the Max Rubner Institute (MRIshort forMax Rubner Institute) and the Nutrition Study EsKiMo II, which was conducted by the Robert Koch Institute (RKI) as part of the nationwide ‘Study on the Health of Children and Adolescents in Germany’ (KiGGS Wave 2), indicate a high consumption of sugar-sweetened beverages among adolescents and young adults. Reducing the consumption of these drinks, particularly in these age groups, could help to reduce the risk of overweight and obesity.

With its ‘National Reduction and Innovation Strategy for Sugar, Fats and Salt in Finished Products’, the German government is pursuing the goal of promoting a healthy lifestyle and reducing the incidenceClose dialogincidenceIncidenceTo glossary of overweight and nutrition-related illnesses. The aim is to reduce the amount of fat and salt used, as well as the amount of sugar. In order to achieve a comparable sweet taste despite the sugar reduction, sweeteners are added to some foods.

The group of dietary fats and fat-like compounds includes triglycerides, phosphatidylcholine and cholesterol. Triglycerides consist of a glycerol molecule to which three fatty acids are bound. These can be saturated or unsaturated and have different chain lengths. The chain length and degree of saturation determine the physical and biochemical properties of the fats.

Humans ingest fats from animal and plant-based foods. They are primarily a source of energy; at around 9 kcal/g or 37 kJ/g, they provide more than twice as much energy as carbohydrates (4 kcal/g or 17 kJ/g). Fats facilitate the absorption of fat-soluble food components, such as fat-soluble vitamins. They are sources of essential fatty acids and carriers of flavourings and aromatic substances. Cholesterol does not provide any energy, but it plays a central role in many metabolic processes; for example, it is used to stabilise cell membranes and as a starting substance for steroid hormones, including vitamin D.

In the long term, a high fat intake can increase the risk of being overweight and becoming obese, as well as the risk of associated illnesses such as type 2 diabetes mellitus, high blood pressure and cardiovascular diseases if the energy balance is unfavourable. According to the German Nutrition Society (DGE), the maximum fat intake should be 30 to 35% of energy.

Proteins are large organic molecules made up of amino acids. They are the basic building blocks of all living organisms and are essential for all life processes.

In the form of enzymes, they act as biocatalysts, serve to regulate DNA activity within cells and as regulatory substances (hormones) between cells; they play a special role in immune defence (immunoglobulins). In addition, proteins can store and transport minerals and oxygen and mediate the transmission of information between cells as well as transport through biological membranes.