Protein is one of the main components of a healthy diet. According to a British study published in Current Opinion in Endocrinology, Diabetes and Obesity , adequate protein intake increases the feeling of satiety, helps control body weight, strengthens muscles and eliminates a number of prerequisites for cardiovascular disease. The optimal daily amount of protein depends on two main factors - current body weight and physical activity .
The current opinion of the World Health Organization is that the approximate daily dose (ODP) of protein for men is 56 g, but according to the respected journal Clinical Nutrition and Metabolic Care , this dosage is below the absolute minimum.
Protein is essential for maintaining strong and healthy muscle fibers, which is why active athletes need more protein than non-athletes. Modern research shows that physically active men need 1.4 to 2 g of protein for every kg of body weight, which is equivalent to 109-155 g per day for 75-77 kg of men.
Although these figures vary according to individual eating habits, the maximum daily intake should not exceed 2.5 g. Quantities above this limit not only lead to obesity and increased risk of cardiovascular disorders , but also create conditions for diarrhea , nausea , vomiting. , headaches and lethal outcome in systemic overdose. 
On the other hand, for non-athletes, the absolute minimum is 0.8 g per kg of body weight per day. Adherence to low-protein diets or deliberate exclusion of sufficient protein leads to weakening of skeletal muscles; progressive loss of muscle mass; weakened immune system, predisposing to more frequent infections; damage to keratin formations - skin, hair and nails; heart failure and other severe symptoms. 
When following a weight loss diet, a golden rule applies : the fewer calories you eat per day, the greater the percentage of them must come from protein. Because burning calories requires muscle mass to expend them, it is advisable, even when dieting, that the daily protein intake does not fall below 0.8 g / kg. 
Men who exercise 3 to 5 days a week and follow a diet at the same time should eat at least one gram of protein per kilogram of body weight, otherwise both sports activity and a strict diet become meaningless.
Daily protein needs can be met with small amounts of a variety of foods rich in different amino acids. 100 g of beef steak contains 36 g of protein, and the same amount of chicken - 30-35 g; 100 g of cheese has 32 g; 100 g of soybeans - 17 g; 100 g of beans - 17 g; 100 g of eggs - 13 g; 100 g of yogurt - 8 g, and 100 g of tuna or salmon - 26 - 28 g.