Seeing a change is 30% gym, 70% diet. Once you’ve decided on your goals, you need to assess your nutritional needs.
You need to work out your Basal Metabolic Rate (BMR), which is the minimum number of calories you need to consume to keep your body ticking over and carrying out it’s basic functions such as cell repair, muscle building, etc.
The quick method assumes that your BMR is 22 calories per kg of bodyweight (females). So for a 60kg female, her BMR will be 1320 cal (60 x 22).
The longer method, which is more accurate is called the Harris-Benedict equation.
BMR = 665 + (9.6 x weight in kg) + (1.8 x height in cm) – (4.7 x age)
So, for a 20 year old female, weighing 50kg and measuring 165cm, her BMR would be:
665 + (9.6 x 50) + (1.8 x 165) – (4.7 x 20) =1348 calories
This equation is accurate except for those who are extremely muscular (require more calories) or extremely overfat (need fewer calories), as it doesnt take into account the amount of lean muscle mass.
Because you will be working out, if you just stuck with the calories on your BMR, you would create a deficit. This would cause your body to not have enough energy to carry out basic cell functions. Your body would go into starvation mode, holding on to every last bit of fat it could for energy. This is NOT what we want to do, we want to encourage our body to shed as much as that as possible.
This is where your physical activity level (PAL) comes in to it.
1.0 -Inactive, such as sleeping or lying down1.2 – Sedentary, such as sitting or a desk job with no physical activity
1.5 – Moderately active, such as a job that requires some physical activity or office workers who work out
1.7 – Active, carrying out gentle exercise or daily walking, jobs including agriculture or construction
2.0 – Very active, such as moderate daily training/exercise, jobs including military, heavy construction
2.2 – Extremely active, strenuous daily training/exercise e.g a professional athlete
Multiply your BMR by your PAL to work out your daily calorie needs to maintain your current weight.
So say our 20 year old female from Step 1 is moderately active, working out 3-4 days a week, but has a desk job. Her PAL would be 1.5
Daily Calorie Needs = 1348 x 1.5 = 2022 calories.
If your current PAL is sedentary, but you plan to work out moderately, then work out your calorie needs for that PAL, not your current one.
If your plan is to lose fatt then you need to carry out a calorie deficit. There are two ways to do this:
- Reduce your calorie intake by 500 kcal per day. There are 3500 kcal per 1lb of fat. In our example, that would be 1522 kcal/day
- Reduce your calorie intake by a percentage. 10-20% of your intake is recommended for healthy fat loss. In this example, that would be between 1617-1820 kcal/day.
Now you should work out your macronutrient percentage. This means protein, carbohydrates and fats. Do you want to reduce your carbs (not cut them out completely) or increase your protein intake (recommended for promoting lean muscle growth and keeping you fuller for longer). Reducing saturated fat is always good. Try not to reduce too much fat – unsaturated fats are very good for you.
The ratios at which you allocate your macronutrient calories are completely dependent on your body type, your personal preference and how it makes you feel.
Click here for a good article describing general starting ratios for your body type, the author describes it very well and I saw no sense in repeating what he says!
When you’ve decided on the ratio you’d like to go with, you can convert those figures into grams. This will help you know roughly how many calories your consuming without become a calorie counting obsessive – that isn’t what living a healthy lifestyle is about, but everything in moderation.
- protein (there are approximately 4 calories per 1g of protein)
- carbs (there are approximately 4 calories per 1g of carbs)
- fats (there are approximately 9 calories per 1g of protein)
So to work this out, take your macronutrient percentage out of your total daily calories and divide that number by the macronutrient cal:gram ratio. For example, say you have a daily calorie intake of 1700 calories, and decide that you want your protein to be 35% of that.
35% of 1700 = 595 calories.
595 cal/4 (cal/gram) = 148.75g of protein per day.
You can do the same for fat and carbs, then divide the total grams by the number of meals you plan to eat a day. You should aim for 5-6 small meals per day to keep up your metabolism throughout the day.
148.75/5 (meals per day) = 29.75g of protein per meal
I really hope this has been insightful and helpful for anyone who has taken the time to read it!
- Boost Weight Loss by Knowing Your BMR (everydayhealth.com)
- The basics of nutrition (thekensingtonstudio.wordpress.com)