The Food and Nutrition Board sets the AMDRs (Acceptable Macronutrient Distribution Ranges). This is a general recommendation for individuals:
- Fat: 20-35%
- Carbs: 45-65%
- Protein: 10-35%
Proteins: large, complex compounds consisting of many amino acids connected in varying sequences and forming unique shapes.
- The primary function of protein is to build and repair body tissues and structures. It is also involved in the synthesis of hormones, enzymes, and other regulatory functions. Additionally, protein can be used for energy if calories or carbohydrate are insufficient in the diet.
- Other functions include: structure, enzymes, hormones, antibodies, fluid balance, acid-base (pH) balance, channels and pumps, and nutrient transport.
- They provide 4 calories per gram.
- Protein deficiency can increase susceptibility to infections as well as impair digestion and absorption of other nutrients. The body may break down body tissue such as muscle tissue and organ tissue for use as a protein source.
- Protein excess can be stored as fat and increase risk for osteoporosis, heart disease, cancer, and gout.
- Balance in the diet is essential. Protein percentage in relation to the other macronutrients (carbohydrates and fats) is 10-35% of the nutritional diet.
- Muscle-building activities, such as intense weight training, increase protein need much less than many people think. The typical American diet provides an ample amount of protein for most people, even bodybuilders.
- Extra protein does not build muscles; only regular workouts fueled by a mix of nutrients can achieve this goal.
- Protein intake of 1.4-2.0 g/kg body weight per day for physically active individuals is not only safe, but may also improve adaptations to exercise training.
- Studies show that endurance athletes involved in heavy training require 1.2-1.4 g/kg body weight protein per day.
- Complete (high-quality) proteins: proteins that supply all of the indispensable amino acids in the proportions the body needs
- Incomplete (low-quality) proteins: proteins that lack one or more amino acids
- Animal foods generally provide complete protein
- The protein isolated from soybeans also provides a complete protein equal to that of animal protein. Soybeans also contain zero cholesterol and saturated fat
- For a list of complete proteins (protein that contains all 9 essential amino acids): https://en.wikipedia.org/wiki/Complete_protein
For individuals pursuing body-fat reduction, body-fat loss goals require that a caloric deficit be maintained until the goal is reached. During a negative energy balance, amino acids are used to assist in energy production. This is called gluconeogenesis. Anaerobic or aerobic exercise depletes glycogen, increasing gluconeogenesis. The increase in gluconeogenesis is supported by the release of branched-chain and other amino acids from structural proteins to maintain glucose homeostasis (good balance) during exercise. A hypocaloric diet establishes less-than-favorable glycogen stores, and when this is combined with increased glycogen demand during exercise, protein’s energy utilization is increased. The amount of lean body mass lost in persons in a negative energy balance can be reduced by increasing the amount of protein in the diet, leading to a more rapid return to nitrogen balance. Several studies show that an increase in protein utilization during a hypocaloric diet will produce effects that can be exacerbated by exercise.