When starting your nutritional transformational journey it is important to address out of three macros first protein. Let's look into why.
Protein is an important component of every cell in the body. Hair and nails are mostly made of protein. Your body uses protein to build and repair tissues. You also use protein to make enzymes, hormones, and other body chemicals. Protein is an important building block of bones, muscles, cartilage, skin, and blood.
Potential beneficial outcomes associated with protein ingestion include the following:
- increased satiety—protein generally increases satiety to a greater extent than carbohydrate or fat and may facilitate a reduction in energy consumption under ad libitum dietary conditions;
- Increased thermogenesis—higher-protein diets are associated with increased thermogenesis, which also influences satiety and augments energy expenditure (in the longer term, increased thermogenesis contributes to the relatively low-energy efficiency of protein); and
- Maintenance or accretion of fat-free mass—in some individuals, a moderately higher protein diet may provide a stimulatory effect on muscle protein anabolism, favoring the retention of lean muscle mass while improving metabolic profile. Nevertheless, any potential benefits associated with a moderately elevated protein intake must be evaluated in the light of customary dietary practices and individual variability.
Protein is the most effective food macronutrient providing a satiating effect. Thus, formulating foods with increased protein contents can help to modulate food intake, promoting body weight loss and body weight maintenance thereafter. Mechanisms explaining protein-induced satiety are primarily nutrient-specific, but they are of course not mathematically related to satiety. Different proteins cause different nutrient-related responses of anorexigenic hormones. Glucagon-like peptide-1 (GLP-1) release evoked by a high protein meal is stimulated by the carbohydrate content. Also, cholecystokinin (CCK) and peptide YY (PYY) release is stimulated by a high-protein meal. Sensory, cognitive, post-ingestive and post-absorptive signals will determine jointly the feeling of satiation and satiety.
In this issue of the Journal, Weigle et al (3) showed that an increase in dietary protein from 15% to 30% of energy and a reduction in fat from 35% to 20%, at a constant carbohydrate intake, produces a sustained decrease in ad libitum calorie intake and results in significant weight loss. They sequentially assigned 19 persons to the following diet regimens: 2 wk of a weight-maintenance diet (15% of energy as protein, 35% as fat, and 50% as carbohydrate), 2 wk of an isocaloric diet (30% of energy as protein, 20% as fat, and 50% as carbohydrate), or 12 wk of an ad libitum diet (30% of energy as protein, 20% as fat, and 50% as carbohydrate). They found that the subjects felt more satiated with the isocaloric high-protein diet than with the weight-maintenance diet. When the subjects were given the possibility to regulate their energy intake under the ad libitum conditions, spontaneous calorie intake decreased by 441 kcal/d, body weight decreased by 4.9 kg, and fat mass decreased by 3.7 kg. We do not yet understand how protein increases satiety. Weigle et al found that the effect could not be explained by changes in the hunger hormone ghrelin or in the satiety hormone leptin.