To begin, we must consume more calories than we expend in total energy. This is dependent on a number of factors, including: Basal metabolism is influenced by a variety of factors, including age, gender, height, weight, fat-free mass, and fat mass. The energy required to absorb and digest food, as well as the metabolic reaction to the food consumed. Physical activity that varies from day to day. This is the second-largest component, after basal metabolic rate; and physiological state - development, pregnancy, lactation, and so on. We must add extra calories after we have calculated how many calories burn per day. It is estimated approximately that to gain 1 kg in a week, we will need about 7000 kcal. This means that if we eat an extra 1000 kcal every day, we should gain 1 kg within a week.
To estimate our weight gain calorie by hand, we need to follow these steps:
1. Calculate the basal metabolic rate (BMR) using the Mifflin-St Jeor formulas:
BMR (kcal/day)men = 10 × weight (kg) + 625 × height (m) − 5 × age (y) + 5
BMR (kcal/day)women = 10 × weight (kg) + 625 × height (m) − 5 × age (y) − 165
BMR is the amount of energy a human body uses when it is at rest. In other words, it’s the amount of energy needed to support bodies vital functions: breathing, blood circulation, controlling body temperature, brain, etc.
2. Calculate the total daily energy expenditure (TDEE) which estimates our total daily energy expenditure, and helps us to find out how many calories we burn every day.
First, choose the index of your physical activity level (PAL) from one of the following:
- little/no exercise: 1.2;
- light exercise 1-2 times/week: 1.375;
- moderate exercise 2-3 times/week: 1.55;
- hard exercise 4-5 times/week: 1.725;
- physical job or hard exercise 6-7 times/week: 1.9;
- professional athlete: 2.4.
Multiply BMR and PAL to determine the total daily energy expenditure, i.e.
TDEE (kcal/day) = BMR × PAL
This is the amount of calories we should eat to maintain your weight.
3. Finally, to calculate our daily weight gain calorie requirement (WG(i)) in the i-th week,
depending on the choice 0.5 kg/per week or 1 kg/per week, we use the following formulas:
– If weight gain pace is 1 kg/per week, then
WGmen(i) = (10 × (weight + i − 1) + 625 × height − 5 × age + 5) × PAL + 1000
WGwomen(i) = (10 × (weight + i − 1) + 625 × height − 5 × age - 161) × PAL + 1000
– If weight gain pace is 0.5 kg/per week, then
WGmen(i) = (10 × (weight +
i − 1
2
) + 625 × height − 5 × age + 5) × PAL + 500
WGwomen(i) = (10 × (weight +
i − 1
2
) + 625 × height − 5 × age - 161) × PAL + 500
For many, increasing daily calories by 5 to 10% is sufficient in promoting lean muscle growth. But there may be some differences in calorie needs per person based on starting body composition and level of training. If you are less trained, you may have more success putting on lean mass in a surplus, but could also find that you are able to lose fat and gain muscle at the same time. Suggested daily calorie intake is
- 45-65% energy from carbohydrates (we use 60% in our calculator):
Carbohydrates =
60
100
WG(i)
- 10-35% energy from proteins (we use 12.5% in our calculator):
Proteins =
12.5
100
WG(i)
- 20-35% energy from fats, (we use 27.5% in our calculator):
Fats =
27.5
100
WG(i)