|Body Mass Index||BMI: tbd|
|BMR (Schofield Formula)||tbd Calories/day|
BMI, BMR, and TEE Calculator
This page provides a calculator for common weight-related measurements such as body mass index (BMI), basal metabolic rate (BMR), and total energy expenditure (TEE). These measurements and their limitations are explained below.
Discussion and Explanation of Computations
Body Mass Index (BMI)
What it is: “[BMI is] an indicator of body fat content, which otherwise can be measured with reasonable accuracy only by methods that tend to be complicated, indirect, inconvenient, and expensive.” See Nestle Why Calories Count at Kindle Locations 2421-2423.
Limitations: And on the problems with the measure and its general utility: “[BMI] cutoff points are arbitrary. The BMI penalizes people with relatively high muscle and bone mass, which do not carry the same metabolic risks as body fat. But by and large the BMI is a useful—a good enough—starting point for evaluating the health risks of excessive calorie intake and its consequences.” See Nestle at Kindle Locations 2423-2427 (emphasis added).
Computation: This is simple division of your weight in kilograms over the square of height in meters. If your BMI is less than 18.5 you are categorized as underweight. If your BMI is over 25 you are categorized as overweight or obese. The obesity category starts at a BMI of 30.
Basal Metabolic Rate (BMR)
What it is: “Physiologists use the term basal metabolic rate (BMR) to refer to the exact number of calories required to support [basic life] functions each day. The BMR is measured in calories per day…” See Nestle at Kindle Locations 993-995.
Limitations: Keep in mind that ”to maintain [your] body weight, [you] must eat more than [the BMR] amounts. How much more depends mostly on [your] level of physical activity and, to a much smaller extent, the kinds of food [you] eat…” See Nestle at Kindle Locations 1078-1080.
Computation: Per Marion Nestle’s recommendation (Nestle at Kindle Location 1061), the
Schofield equation for BMR is used. See WHO Energy and Protein Requirements 1985:Annex 1 (online at FAO, Corporate Dcoument Repository). BMR is only computed for ages 18 and up.
Total Energy Expenditure (TEE)
What is it: BMR + thermic effects of food + your physical activities. Like BMR, TEE is measured in calories per day. BMR accounts for 50-70% of TEE.
Limitations: Nutritionists often speak in terms of EER (estimated energy requirement) which will generally be close to TEE, Marion Nestle explains: “[Nutritionists] use something called the estimated energy requirement (EER). This we define as the average daily intake of calories needed to maintain a healthy and relatively constant body weight in men and women of various ages, weights, heights, physical activity levels, and life stages.” Nestle at Kindle Locations 1421-1423.
Computations: Computes the total energy expenditure (TEE) per pages 204-205 of Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2005) using the “low active” PA values. Online here. This is the same formula used by Weight Watchers as part of the computation of daily targets in the 2011-2012 PointsPlus system.