How to create a diet: part 1
As you gathered form the title, the purpose of this article is to describe how a diet should be set up, or, at least how I think it should. The inspiration for this article came from the observation (personally, as well as overhearing conversations and scrolling through message boards) that many people are confused about how to set up a diet, whether it is a maintenance diet, fat loss diet or a mass gaining diet. This confusion among the lay public is unsurprising given the popularity of diets such as Barry Sears’s The Zone Diet (which centers around a 40:30:30 ratio of calories from carbohydrates, fat and protein, respectively), Weightwatchers (which focuses more on restricting the total quantity of food consumed by way of counting calories and “points”) and Dr. Atkins’ New Diet Revolution (a virtually zero carb, high fat, moderate protein diet).
There are literally hundreds of these types of diets that are almost exclusively intended for “weight loss”, or fat loss; the term that I prefer. Given the vast apparent difference between such diets, they all share a common theme; to trick you into eating less one way or another, whether this is by counting X, eliminating Y, combining such and such, not eating after a certain time, only eating certain things on specific days etc. Basically, success (i.e. fat loss) is achieved (at least in the short term) with such diets due to calorie restriction, whether the author admits to this fact or not. Another limitation of such diets is that they typically involve a one-size fits all approach with minimal, if any, consideration of individual differences in physiology, goal(s), dietary preferences etc. This is probably why some people swear by one type of diet over another and vice-versa. When in fact, neither are “better” per se. Rather, it is more likely that a favorable diet for a given individual “ticks more boxes”, whether it be physiological, psychological or just integrates with their current lifestyle better.
Take The Zone Diet for instance, the amount of each macronutrient consumed at fixed macronutrient percentages is entirely dependent on the total calorie intake. For example, an 1800 kcal diet for an untrained female looking to lose fat would yield a macronutrient intake of 180:60:135 g of carbohydrate, fat and protein, respectively, which actually isn’t a bad starting point. Conversely, if a male endurance athlete with a daily energy requirement of 4000 kcal set their diet up in this manner, it would yield a macronutrient intake of 400:133:300 g of carbohydrate, fat and protein, respectively, which would be way to much protein and fat for their specific needs, and would compromise carbohydrate intake. Furthermore, attempting to stick to a specific macronutrient ratio on a meal-by-meal basis would become a
full-time job, even for the most dedicated dieters (read bodybuilders!).
Estimating caloric and macronutrient requirements
The introduction has hopefully made a decent enough case for an individualised yet simplistic approach to setting up a diet, as opposed to having people gambling with a fad diet in the hope that it pays off. The framework that I use focuses on setting individual macronutrient requirements in four steps. After estimating total maintenance calories (1), I set protein (2), then fat (3) and let carbohydrate make up the remainder (4).
1. Estimating total energy expenditure
When speaking of a maintenance caloric intake, what I really mean is a caloric intake that will more or less match energy expenditure, hence, maintain body mass. Total energy expenditure (TEE) consists of resting energy expenditure (REE) or basal metabolic rate (BMR), thermic effect of activity and the thermic effect of food (TEF).
While technically not the same thing, REE and BMR are often used interchangeably, and for all practical purposes, their differences are nothing to be concerned with when estimating caloric needs. REE/BMR pretty much represents the energy cost of sustaining life and is measured at rest in a fasted state. TEA includes the energy cost of all physical activity, both voluntary and involuntary (i.e. non-exercise activity thermogenesis). Non-exercise activity thermogenesis (NEAT), which makes up approximately 15-30% of TEA, includes things such as shivering, fidgeting and anything else that involves movement but isn’t really classed as exercise. TEF accounts for the average thermic effects of the macronutrients during digestion and roughly accounts for 10-15% of TEE. The TEFs for the individual macronutrients are: protein (25-30%), carbohydrate (6-8%), fat (2-3%).
As TEE is made up of the sum of REE/BMR, TEA and TEF, we have to be able to measure, or, at least estimate these individual components in order to work out an individual’s daily caloric requirements. Since most reading this won’t have access to a lab in order to measure REE/BMR, we have to estimate it using one of many prediction equations. The ‘Harris-Benedict’, ‘Mifflin-St Jeor’ and ‘Owen’ equations are the most popular ones in use, with the ‘Mifflin-St Jeor’ equation being the most reliable of the three. The equations are outlined below:
Men: 66 + (13.75 x weight) + (5 x height) – (6.76 x age) Women: 655 + (9.56 x weight) + (1.85 x height) – (4.68 x age)
Men: (10 x weight) + (6.25 x height) – (5 x age) + 5 Women: (10 x weight) + (6.25 x height) – (5 x age) – 161
Men: 879 + (10.2 x weight) Women: 795 + (7.2 x weight).
Men: 24.2 x weight. Women: 22 x weightSource: josephagu.com