introduction
it’s safe to say that most carbohydrate recommendations that you will see are put in terms of percentages, you should be eating 45% of your calories as carbs, or 65% or whatever number is being used.
As i discussed in diet percentages: Part 2, i don’t like this method. Rather, putting nutrient recommendations in terms of grams per kilogram or per pound is generally more valid (with one exception i discuss below). The percentages are simply meaningless without knowing how many carbohydrates are being provided in terms of gram amounts.
In that context, a typical ketogenic/low-carbohydrate diet might contain 0.5 g/lb (~1 gram/kilogram) of carbohydrate. An average moderate carb diet (such as the zone or duchaine’s isocaloric diet) might contain 1 g/lb (~2 g/kg) of carbohydrate or slightly more. A typical high-carbohydrate diet would, of course contain more than that (perhaps 2-3 g/lb or more). Typical recommendations for endurance athletes are in the 3-4 g/lb (6-8 g/kg) range and carb-loading may require 5-8 g/lb (10-16 g/kg) of carbohydrate.
Still, whether you’re looking at carb recommendations in terms of percentages of g/lb (g/kg), there is still a huge discrepancy between different experts. Some recommend lots of carbs, some recommend medium amounts, some recommend almost none.
Who’s right? Well, i am. Because rather than giving some single carbohydrate recommendation (that can’t possibly take into account all possible situations), i look at the individual and their needs to decide how many carbohydrates should be consumed daily.
Which is what i’m going to look at in detail in this article. The punchline, of course is that i’ll end up concluding that how many carbohydrates someone needs (or should consume) daily depends on the same factors that affect other nutrient recommendations: Goals, preferences, types and amounts of activity, and our old friend, genetic variation. By the end of the discussion, i’ll have set both minimum and maximum intake values depending on different conditions that might crop up. Let’s start with minimum amounts.
Are carbohydrates essential?
Despite oft-heard claims to the contrary, there is no actual physiological requirement for dietary carbohydrate. Even the rda handbook acknowledges this, right before recommending that a prudent diet should contain a lot of carbohydrates.
To understand why carbs aren’t essential, i need to discuss the concept of an essential nutrient briefly. And, in brief, an essential nutrient is defined as:
1.any nutrient that is required for survival.
2.can’t be made by the body.
Quoting from my own rapid fat loss handbook:
The second criterion is the reason that dietary carbohydrate is not an essential nutrient: The body is able to make as much glucose as the brain and the few other t
ues need on a day-to-day basis from other sources. I should mention that the body is not able to provide sufficient carbohydrate to fuel high intensity exercise such as sprinting or weight training and carbs might be considered essential for individuals who want to do that type of exercise. I’ll come back to exercise later in this article.
But from the standpoint of survival, the minimum amount of carbohydrates that are required in a diet is zero grams per day. The body can make what little it needs from other sources. What, you ask, are those other sources? Read on.