inHUMAN Nutritions

How Many Calories to Consume When Dieting


How Many Calories to Consume When Dieting
Posted on: 2013-07-31 08:28:25 Ft.

Losing weight is no easy matter. One needs to be disciplined and prepared, but not only this, they need to have a plan. So where does one first start when developing a plan? Well, the first thing one would want to do is get an idea of how many calories they should consume to optimize weight loss. There are several ways to do this, but we’re going to review the gold standard of them all. Basically, we’re going to let you in on a secret that contest prep specialists and nutritionists use to get people shredded! Just keep in mind that the advice that follows is for informational purposes and one should always consult a physician or qualified health care practitioner before starting any nutritional program or making any decision that may affect the health and welfare of that individual.

Harris/Benedict Equation

The Harris/Benedict Equation is an algorithm used to estimate one’s basal metabolic rate (BMR) and daily calorie expenditure. Essentially, it’s used to figure out how many daily calories someone requires to maintain his or her current body weight and it’s a good starting point to base a diet on.

As you’ll see, the Harris/Benedict equation factors in weight, height, age and activity level. Additionally, there’s a separate equation for both sexes. We’ve listed a “revised” algorithm below as the original is seen as a bit antiquated. (Note: The original Harris/Benedict equation was first published in 1918.) Also, one has to determine their appropriate activity level and then input the corresponding value into the equation, which is also provided below.

Men BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) - (5.677 x age in years) X Activity Level
Women BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) - (4.330 x age in years) X Activity Level


ACTIVITY LEVEL CORRESPONDING VALUE
Little to no exercise 1.2
Light exercise (1–3 days per week) 1.375
Moderate exercise (3–5 days per week) 1.55
Heavy exercise (6–7 days per week) 1.725
Very heavy exercise (twice per day, extra heavy workouts) 1.9

 A Few General Guidelines

  • The Harris/Benedict equation should be seen as a starting point and not as an absolute indicator of calorie requirements. Everyone is different and everyone will have different requirements. Therefore, adjustments will need to be made to tailor the diet specifically for the individual.
  • The Harris/Benedict equation is based on the assumption that the individual has a normal body composition with an average muscle mass to fat mass ratio. Therefore, the value may be too low for someone with a very lean, muscular physique. Oppositely, the calculation may be too high for someone who is obese.
  • As mentioned, the Harris/Benedict equation is a mathematical equation to figure out daily calorie requirements to maintain body weight. Therefore, if the goal is to reduce body weight then one should consume fewer calories, right? Not necessarily. The argument for doing so is usually based on the fact that there is 3500 k/cal in a pound of fat and, therefore, if one wants to lose a pound of fat a week then they need to reduce their daily caloric intake by 500 k/cal (3500 k/cal divided over 7 days). This may have some merit for a heavier set person, but for someone who weighs far less a 500 k/cal daily reduction may be too much and detrimental. Also, you need to consider the next point when developing a diet, but before you read on, stick with the value given from the equation at first before making adjustments.
  • One must consider the macronutrient (protein, carbs and fat) breakdown or ratio of the calories they consume when trying to lose weight. A diet too high in carbs and fat is generally not conducive to weight loss. A general recommendation is to follow a high-protein, moderate-carb, low-fat diet. For example, one could use a macronutrient ratio of 45:35:20 (protein:carbs:fat) and can see a benefit from doing so. However, once again, everyone is different and everyone will have different requirements. Ultimately, one must figure out what works best for them.
  • An individual must be cognitive of their body’s feedback to a diet:

o   If one is gaining weight, they may have to adjust their daily calorie intake and/or the macronutrient ratio of those calories. However, they may be trading off fat for muscle, which is definitely not a bad thing. Therefore, they would not necessarily need to make any changes. In other words, sometimes one has to go by what they see in the mirror and not what they see on the scale. 

o   If one is not losing weight, they also may need to make adjustments, but once again, they could be trading fat for muscle.

o   If one is feeling lethargic or rapidly losing strength/stamina/endurance during training, then it’s a good indication that the calories are either too low or the macronutrient profile is too low in carbs and/or fat. Either way, adjustments will need to be made. One way to help alleviate this problem is to periodically have a cheat meal or day once every 5-7 days. However, if the problems persist, it’s a good indication to adjust the daily calories and/or macronutrient profile.

o   If one is losing too much weight too fast then the total calories and/or macronutrient profile may need to be adjusted. Just keep in mind that the first few weeks on a calorie-reduced diet can show the biggest weight reductions when compared to the subsequent weeks to follow. Typically, one loses more weight in the beginning. (Note: A general recommendation for weight loss is 2 pounds a week.)

  • As mentioned, adjustments will continually need to be made. The key is to make small adjustments as one progresses to continue to progress. If one changes too much, one may have changed something that was working. However, keep in mind that if everything is working well then there’s no need to make any adjustments. ‘Cause if ain't broke, don’t fix it!

All of the content on this website is only for informational purposes. The information contained here should not be construed as medical advice and is not a substitute for professional medical advice, care, diagnosis, or treatment. Always consult a medical professional before starting any supplement, exercise or nutritional program.