One approach is to spread carbohydrate intake throughout the day in small amounts.
While this may minimize insulin response, it should be noted that 5-6 grams of carbohydrate per
meal is not much carbohydrate. Some individuals may wish to have all of their daily
carbohydrate at one main meal, such as a large salad with dinner or lunch. Although this will
cause a slightly greater insulin release than spreading out the same amount of carbohydrate
throughout the day, the low GI of vegetables coupled with the digestion slowing effect of protein,
fat and fiber should prevent an excessive insulin response. Even if a large enough insulin
response occurred to disrupt ketosis, it should be transient and ketosis should resume soon
thereafter.
Summary
Although carbohydrate intake must be severely restricted on a SKD, a diet completely
devoid of carbohydrate is impossible to achieve in practice and would be monotonous in any case.
Depending on factors such as protein intake, a carbohydrate intake of 30 grams per day or less
will generally allow the induction of ketosis although this varies from person to person. As a
general rule, low GI carbohydrates such as vegetables are the best source as they have the least
effect on insulin release. Fruits and starches should generally be avoided on a SKD. The daily
carbohydrate amount can either be spread throughout the day or eaten all at once.
Section 3: Protein and the SKD
Having discussed the details of carbohydrate intake on a standard ketogenic diet (SKD)
last chapter, we can now discuss issues pertaining to protein. Although carbohydrate intake is
arguably the most important aspect of successfully inducing ketosis, protein intake is extremely
important in order to prevent muscle loss. While an easy solution is to simply eat as much
protein as possible, too much protein can prevent ketosis as well, disrupting the adaptations
which ketogenic dieters seek. Therefore, protein intake must fall within a narrow range: high
enough to prevent muscle loss but low enough that ketosis is not disrupted.
A common criticism of the ketogenic diet is that ketosis is catabolic. This is true in that
any diet which is restricted in calories is catabolic. The question, addressed in chapters 5 and 6,
is whether the ketogenic diet is inherently more catabolic than other dietary approaches.
As discussed in chapter 6, one of the problems with many diet studies comparing ketogenic
to non-ketogenic diets was the provision of insufficient dietary protein to both groups, causing too
much protein loss in both groups. The interpretation given was that the ketogenic diet had no
benefit over a non-ketogenic diet when the proper interpretation was that both diets were
ineffective in preventing muscle loss. With adequate protein intake, muscle loss should be
minimal.
For any diet to minimize muscle loss, it must contain sufficient amounts of high quality
protein. Due to the high intake of animal proteins, ketogenic diets will tend to contain high quality
proteins by default.