Even if you solely eat healthy stuff, you can gain (and yes, also lose) weight and reduce your health. It is as simple as it is: consuming too many calories can cause weight gain and in the long (long, long, loooong term for some of us) diseases linked to obesity. Consuming too little calories can cause malnutrition and in the long term (and sadly in the short term for some of us) malnutrition and diseases and complaints (such as loss of energy, bone decay, hair loss etc.) linked to that.
I personally started monitoring my food intake many years ago at a point that I began working out more often. While they say working out should give you loads of energy, I felt tired as hell! No wonder, since it seemed that I burned off so many calories, that I unknowingly created a huge defict and so, was seriously undereating and in danger of malnutrition!
Step 1: calculate your BMR
So how did I know that I wasn’t consuming enough? Well, in 1919, there were these two guys, Harris and Benedict, who carried out the “Biometric Study Of Basal Metabolism In Man”. Their study concluded that the equation BMR = 655.0955 + (9.5634 x weight in kg) + (1.8496 x height in cm) – (4.6756 x age in years) is the best method used to estimate a woman’s basal metabolic rate (BMR) and daily kilocalorie requirements (equation for men: BMR = 66.4730 + (13.7516 x weight in kg) + (5.0033 x height in cm) – (6.7550 x age in years)).
Step 2: activity level
It doesn’t stop there. In step 2 you’ll multiply your BMR with your activity level:
Sedentary. Little to no regular exercise.
Mild activity level: Intensive exercise for at least 20 minutes 1 to 3 times per week. This may include such things as bicycling, jogging, basketball, swimming, skating, etc. If you do not exercise regularly, but you maintain a busy life style that requires you to walk frequently for long periods, you meet the requirements of this level.
Moderate activity level: Intensive exercise for at least 30 to 60 minutes 3 to 4 times per week. Any of the activities listed above will qualify. (factor 1.55)
Heavy or (Labor-intensive) activity level: Intensive exercise for 60 minutes or greater 5 to 7 days per week (see sample activities above). Labor-intensive occupations also qualify for this level. Labor-intensive occupations include construction work (brick laying, carpentry, general labor, etc.). Also farming, landscape worker or similar occupations. (factor 1.7)
Extreme level: Exceedingly active and/or very demanding activities: Examples include: (1) athlete with an almost unstoppable training schedule with multiple training sessions throughout the day (2) very demanding job, such as shoveling coal or working long hours on an assembly line. Generally, this level of activity is very difficult to achieve. (factor 1.9)
Is your head spinning from all these numbers? Use the calculator and prevent consuming too little (or too much):
- Atwater WO (1899), Benedict FG, Smith AW, e.a. Experiments on the metabolism of matter and energy in the human body. Rev. ed. Published 1899 by Govt. Print. Off. in Washington
- Jönsson T (2010), Granfeldt Y, Erlanson-Albertsson C, Ahrén B, Lindeberg S. A paleolithic diet is more satiating per calorie than a mediterranean-like diet in individuals with ischemic heart disease. Nutr Metab (Lond). 2010 Nov 30;7:85.
- Urban LE (2010), Dallal GE, Robinson LM, Ausman LM, Saltzman E, Roberts SB. The accuracy of stated energy contents of reduced-energy, commercially prepared foods. J Am Diet Assoc. 2010 Jan;110(1):116-23.