Macronutrients consist of carbohydrate, protein, and fats. They are all necessary in the diet but in varying percentage points. These 3 macronutrients make up your total daily calories in a food. They break down in your body to provide you with energy, tissue building and repair, and insulation (respectively).
The first step in learning what your personal needs are, you need to calculate your Resting Energy Expenditure. I will volunteer to be the example!
Step 1: calculate your body weight in kg by dividing your weight in pounds by 2.2
140/2.2= 64 kg
Step 2: use the chart above (sorry it's a little blurry!) to calculate your REE.
(14.7x64)+496= 1,436 calories
(1436)(1.6)= 2,299 calories
(1436)(2.4)= 3,447 calories
Average: 2, 873 calories
|I used slightly different percentages; the percentages I used were for active individuals. There is wiggle room!|
Carbohydrates are essential for energy. The brain will ONLY use glucose (the simplest carbohydrate) for energy. So if you are low on glucose, you can ultimately pass out. Under NO circumstances will your body use fat or protein for energy in the brain... are you beginning to see why low carb diets aren't the greatest idea? A person generally requires 45-65% of their total daily calories to come from carbohydrates. The range is rather large because of varying levels of activity; a sedentary person will need less than an athletic individual. There are 4 kcals per gram in carbohydrate.
EX: A food has 25 grams of carbs
(25 grams)(4 kcal)=100 kcal of carbohydrates
To calculate your recommended carbohydrate range, multiply your REE calories by 45% and 65%. Then divide the calories by 4 kcals to calculate the grams. Take the average for a solid number idea.
(2873)(.45)=1,293 calories / 4kcal = 323 g CHO
(2873)(.65)=1,867 calories / 4kcal= 466 g CHO
Average: 395 g CHO per day
Fats can also be used for energy but also help to insulate the body and the nerves. Too much fat isn't good of course, but neither is too little. The body generally requires 20-35% of your total calories to come from fat. There are 9 kcal per gram in fat.
EX: A food has 10 grams of fat
(10 grams)(9 kcal)= 90 kcal of fat
To calculate your recommended fat range, you will do the same thing as with carbs except within the range of 20-35% and divide by 9 kcals to calculate the grams.
(2873)(.20)= 575 calories/ 9kcal = 64 g fat
(2873)(.35)= 1,055 calories/ 9kcal = 111 g fat
Average= 88 g fat per day
Protein lends very little energy to the body but is very important to tissue building and repair. Unfortunately your body doesn't store a ton of protein, and for that reason you only require 15-20% of your total calories to come from protein. Your body will use the protein, or it will convert it into fat. Most people can only absorb around 25 grams of protein at once, so that 50 gram protein shake isn't doing too much help for you. I don't care how epic your workout was, you only require 6-20 grams of protein after it and it should be coupled with carbohydrates within the first 2 hours. Then again every 3-4 hours after that. Your stomach will only absorb water and alcohol, so you have to give your body time to digest it and then absorb it in the small intestine. As I said, your body generally requires 15-20% of your total calories to come from protein so let's calculate. Similar to carbs, there are 4 kcals per gram in protein.
EX: A food has 12 grams of protein
(12 grams)(4 kcals)= 48 kcal of protein
To calculate your recommended protein range, do the same as before except with 15-20% ranges and divide by 4 kcals.
(2873)(.15)=431 calories / 4kcal = 108 g protein
(2873)(.20)= 575 calories/ 4 kcal= 144 g protein
Average= 126 g protein per day
Keep in mind, too much protein can lead to ketosis. Ketosis can lead to organ failure and is caused by a build up of Ketones, a waste product of protein and the nitrogen group. This is another reason low carb/ high protein diets are NOT a good idea.
Every macronutrient is important, and have their benefits but too much of anything can be bad. This is why everything in moderation works and fad diets do not. The body needs all these things, so don't think low carb or fat free diets are ever okay- especially if you are active! The body is a very intricate machine, take care of it!
As for the EX I used, to calculate the total calories of that food, you would simply add up all the kcals. So, 100+90+48=238 total calories in that food!
Food is fuel, not the enemy. Eat to Live, don't Live to Eat.