Proteins are an important macronutrient of food which is essential for all life processes. The word protein is derived from the greek word "proteus" which means "first" and hence are considered to be of primary importance. Proteins are the building blocks of life and the human body requires approximately 1 gram/kg bodyweight of protein everyday to stay healthy. Proteins are required for body growth and development, cellular processes, muscle health, tissue repair, immune response, hormone synthesis, transport of various elements in blood, maintaining blood viscosity and PH and synthesis of new cells.
Bariatric surgery induces a catabolic response in the body and this can lead to muscle breakdown along with fat burning particularly in the phase of rapid weight loss. Thus patients who have undergone bariatric surgery typically require more protein to prevent loss of lean body mass. The patients who have undergone bypass procedures may require even greater amounts to compensate the losses due to malabsorption. Typically patients who have undergone bariatric surgery may require 1.5-2g/kg of protein which amounts to 80-120 gm of protein per day.
There are different sources of protein in food. They can be divided into vegetarian and animal sources as well solid and liquid protein. The most widely available liquid source of protein is milk which can be fortified with protein powder to increase the protein density. Milk remains the primary source for protein during the first few days after undergoing a bariatric procedure.
Rich vegetarian sources of protein include dairy products, legumes, soyabean, green leafy veggies, nuts, seed and dry fruits. Animal proteins include eggs, chicken, fish, seafood and all kinds of meats. Although many vegetarian sources contain more gram of protein per gram of food consumed, they are considered inferior to animal protein in quality since they do not contain all the essential amino acids.
Each post bariatric surgery meal or snack should comprise at least 40% of calories through protein rich food. The protein rich food should be consumed first as opposed to carbs or fat rich foods since it is considered more important and will contribute to satiety. Often, the requirement of protein would not be met through food alone and this would require protein supplements in form of powder. Protein powder is commercially available in different brands often from different sources but whey protein isolate is the most common and typically would have 40-60% protein per gram.
Protein powder should be taken 2-3 times per day and each serving can contribute between 8-15 grams of protein. The powder can be taken in water or milk and sometimes in shakes or smoothies aa per the patients’ preference. It also available in different flavours to increase the palatability and improve patient dietary compliance.
Proper protein intake after surgery has numerous benefits for the body. It contributes to satiety and hence decreases the total caloric intake. Protein has been found to delay gastric emptying, thus it decreases snacking between meals and as well as late night hunger pangs. Proper protein intake prevents muscle depletion during rapid weight loss and thus maintains lean body mass. Having a higher proportion of lean body mass contributes to increased resting BMR and hence more calories burnt at rest. This also contributes to long term weight loss and prevents weight.