Macronutrients are large food categories of food necessary for energy production. Protein, Fats, and carbohydrates should be incorporated in every nutrition plan. Macronutrient quantity recommendations vary depending on a person's fitness goals, lifestyle, and medical history. There are many different diet trends that encourage drastic changes in macronutrient amounts for weight loss, weight/ muscle gain, metabolic disease, heart disease, or athletes.
MACRONUTRIENTS
There are many different diet trends which encourage drastic changes in macronutrient amounts for weight loss, weight/muscle gain, metabolic disease, heart disease, or athletes. Commonly known diets include: Low-carbohydrate, keto, intermittent fasting. Mediterranean diet, high- protein diets, Zone diet, and other branded quick fixes.
Unfortunately, there is little/ no evidence that a specific diet works better than another. According to a large systematic review of diet comparisons, all diets resulted in decreases of body fat. If the participants were consistent, they lowered their calorie intake by 500 calories per day, and they ate a well-balanced (including all macronutrients) a higher value of participants lost body fat and weight.
Average recommendations for an adult are:
Protein: 08g- 1.6/ kilogram of body weight
Carbohydrates: 4-6g/ kilogram of body weight
Fat: 20-35% of a person's daily intake
WHAT ARE THE BENEFITS OF EATING A VARIETY OF FOODS?
FATS
CARBOHYDRATES
PROTEIN
The importance of protein to maintain health in every diet is evident in research. It’s primary role in the body is cell repair, maturation, enzyme function, and transport carriers of hormones in every body system. Proteins are composed of amino acids. Some are naturally occurring in the body ( Nonessential) and some come from the foods we eat ( Essential). Proteins influence on bone could be from the influence on insulin— like growth factor -1 ( IGF-1). There is very little evidence that a protein diet over 2.5g protein per kg of body weight per day is detrimental to an athletes health. Counter, the more intensely an athlete workouts the higher amount of protein is required for protein synthesis and muscle repair and that a low protein suppresses intestinal calcium absorption and can cause bone loss (Haff, Triplett, 2017).
The theory that high amounts of daily protein will cause long term internal damage to an athletes health has been disproven by short term and long term studies. Previous concerns of high daily protein intake include renal stress, dehydration, gout, bone catabolism and advert impact on diet quality. “Brenner's Hypothesis” is a theory that high amounts of protein in the urea can cause renal damage through increased kidney filtration, but this has been disproved by a long term ten year study. In Lowerys, et at, 2011 long term study he measured renal filtration over an eight year period. One group ate an average diet and the other group pursued a consistently high protein diet of 2.5 g of protein per kg of body weight daily. When participants were measured they did a 12 hour fast and creatinine clearance levels were measured. The athletes had no significant difference in a 12 hour fasted creatinine clearance level test. There was also no difference in serum variables of sodium, potassium, chloride, anion gap, calcium, albumin or phosphorus. When an athlete is on a high protein diet not all of the protein may be utilized by the muscles, so it is unnecessary for the athlete to eat extremely high amounts of protein. Long term studies by Lowery et al, (2011 and 2012) have supported that long term protein ingestion does not damage the renal system,but is properly recycled out of the body in the urea or converted to carbohydrates or body fat. They also concluded that 20g of egg protein was the ideal amount of optimal protein synthesis after a workout. The body recycled the remaining protein or their way to increase in measures with a greater amount of protein ingestion (Lowery, et al, 2012).
The quality and type of protein does play a role in the influence of protein absorption and muscle protein synthesis (MPS). According to the PDCAAS whey hydrolysates from meat, Soy, casein are all considered high quality, complete proteins. Branch chain amino acids, specifically; Isoleucine, leucine and valine are responsible for increasing muscle protein synthesis. These are commonly found in meat and milk sources. Whey isolate is the most concentrated high-quality protein with only 10% of other substances like fat and lactose. Hydrolysate has less influence on MPS then Whey protein but more than soy and casein. Isolates and hydrolysates should be taken during or immediately after exercise, but they digest fast (Lowery at el. 2012) compared the MPS of isolate whey, hydrolysates and casein. The results showed increases of MPS and strength during a unilateral squat set and during rest. Hydrolysate and isolate ingested immediately after the exercise set showed the most increases during a 10-week study. Lowery, et al, also observed decreased body fat percentage and increased strength (Lowery, et al 2012).
Tang et al, 2009 also found increased protein synthesis from consumption of whey hydrolysate, casein and soy protein isolate. Whey is digested quickly and hydrolysates and casein digest slower. Whey impacted MPS significantly more then the other protein sources. MPS increased by 122% whereas soy consumption only increased it by 31%. An observation of Whole milk consumption showed better whole body nitrogen retention at rest and greater skeletal muscle protein accretion after resistance exercise. Casein digests much slower and therefore acts by inhibiting whole body protein breakdown. It is typically recommended to take before bedtime to prevent muscle breakdown during periods of muscle recovery (Tang et, al, 2009).