IMPORTANCE OF PROTEIN

Protein– protein is one of the important macronutrients along with carbohydrates and fat. 1gm protein provides 4 calories. Proteins are composed of long chains of amino acids. Proteins form the major structural components of muscles,brain,skin and hair. The important macronutrient serves as the transport mechanism for iron,vitamins,mineral,fats in the body.

RECOMMENDATION-For adults the recommended daily allowance (RDA) for protein is 0.8 gram per kilogram of body weight per day (g/kg/day). The protein recommendation for endurance athletes ranges from 1.2 to 1.4 g/kg/day. During times of intense training, including resistance exercise, the recommendation increases to 1.6-1.7g/kg/day. protein recommendation varies from 10 to 35% of daily energy intake.

QUALITY OF PROTEIN– Food protein quality is determined by assessing

  • essential amino acids(complete and incomplete protein)
  • digestibility( easily digestible)
  • bioavailability( amount of protein body can absorb and use.)

Factors comes into play while choosing protein sources-

1)protein quality varies- Complete protein-Contains all essential 9 amino acids( histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.) which body cannot produce .Generally animal products contains all essential amino acids( complete proteins) and protein bioavailability is better.while Incomplete protein-lack one or two essential amino acids.

  • Egg milk,soy contains all essential amino acids and are easily digested and absorbed.while animal products have all essential amino acids but lacks  fibers and is not easily digestible.
  • While fruits,legumes,cereals, nuts are incomplete protein must be combined over the course of the day to ensure we get all amino acids.While plant food are incomplete proteins( except soya,quinoa,chia,buckwheat,hemp,flax seeds are complete protein, excellent combination includes grain and legumes( rice and beans),grain and dairy and legumes and seeds.

2)different protein are better different times-

  • Whey protein is rapidly digested and resulting in short burst of amino acids into blood.
  • Whereas casein is slowly digested and releases more prolonged amino acids.

3)High protein diet is not for everybody- People who have preexisting condition  such as kidney disease,diabetes,osteoporosis,liver disease , one should ask RD before adopting high protein diet.

HIGH PROTEIN DIET-While the body has the capacity to store carbohydrate and fat, there is no such storage for protein,body cannot store protein in the form of protein, which is why it must be consumed daily. When too much protein is consumed, its broken into two portion ,one portion  gets excreted in urine as urea. while other portion is converted into glucose if body cannot use it then finally gets stored as fat. Excessive protein consumption, whether from food sources or by liquid or powder supplements, may cause dehydration, as well as negatively impact the kidneys and bones.

PROTEIN BALANCE

  • The continuous recycling of amino acids through removal of amino acids allows the body to carefully regulate protein balance.protein balance is measured in terms of nitrogen balance ( NITROGEN CONSUMED( FROM DIE T and NITROGEN EXCRETED (PROTEIN BREAKDOWN). Body maintain this balance.
  • But sometime the balance is disturbed during the process like low carb diet,ketogenic diet,detox diets, severe infection and trauma( catabolism)
  • While sometimes there is Positive nitrogen balance( where body produces more protein) during pregnancy,childhood and most important in response to resistance training when we overload muscles with weights than the muscles promotes protein synthesis.

Athlete should avoid in any case low carb high protein diet-carbs and protein plays important roles in endurance( any activity more than 30 mins) and resistance training exercise. This exercises stimulates muscle protein synthesis. When Athletes consume high protein diet  does not necessarily means they have positive nitrogen balance,which means they have extra protein store in body it’s not possible. And with minimum glycogen stores they rely heavily on muscle protein for fuel which will worsen athletic performance and muscular strength.

BEST COMBINATION( of carbs and protein)- 6 to 20 gms of protein and 30 to 40 gms of carbohydrates within 3 hours post exercise encourage muscle synthesis. Carbohydrate are important to pair with protein, if insufficient carbohydrates is provided the body’s energy needs and muscle synthesis is compromised. for eg combination of 1 banana with glass of lowfat milk, and 1 whole wheat toast) classic example of combination of carbs and protein which is easily digestible and available.Vegetarians should consume 10% more protein.

AMOUNT OF PROTEIN FROM DIFFERENT FOOD GROUPS-

amount of protein per serving protein
grains(roti,bread,crackers,rice 3g
non starchy veg( ½ cup cooked carrot,cauliflower etc 2g
fruit 0g
dairy (1 cup milk,3/4 c yogurt) 8g
legumes n pulses(1/2 cup) 7g
meat,egg and fish(1 ounce) 7g

There is a common misconception among people that vegetarian people do not get adequate quality and quantity of proteins and hence these people need to take protein supplements,Just because they are incomplete doesn’t make them inferior, they just need to be combined with other food groups. If you are a vegetarian u have to make smart choices it’s still easy to create complementary proteins by mixing and matching vegetarian sources.In fact, if properly and wisely mixed with each other, vegetarian diet can be a good source of quality proteins and fiber. Whereas meats lack fiber and other nutrients .

Here is eg of complementary protein- Most Indian beans are low in methionine and high in lysine, while rice is low in lysine and high in methionine. So rice and beans goes as complete protein.

Some other eg-

  • cerea(poha upma, and milk
  • wholegrain bread and milk
  • quinoa/oats/rice pulav and raita
  • Idli with sambhar
  • tofu curry and rice
  • matar paneer sabji and roti/rice
  • rice and dal(khichdi)
  • curd and rice
  • paneer burji and whole wheat bread
  • Rice and rajma( red kidney beans curry)
  • Hummus on whole-grain bread
  • dosa with peanut chutney/sambhar

Source-ace fitnees.org

Img www.hsph.harvard.edu

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