Similarly, the limited food choices of a ketogenic diet may mean that certain nutrients,
namely those found in fruits and vegetables, are not consumed. As discussed in chapter 7, recent
research has focused on the potential health benefits of phytonutrients, which are only found in
vegetables and fruits. Since some carbohydrates are allowed during any ketogenic diet, limited
intake of these nutrients is possible, but will be less than could be consumed on a balanced diet.
Finally, some individuals may find it difficult to resume balanced dieting after long periods
on a ketogenic diet. Since many individuals gravitate towards a ketogenic diet out of a difficulty,
whether real or perceived, in handling dietary carbohydrates (i.e. hypoglycemia,
hyperinsulinemia), reintroducing carbohydrates in controlled amounts may be difficult. By the
same token, some individuals find it easier to control a previously excessive carbohydrate intake
after a ketogenic diet. For example, many individuals have reported a decreased taste for refined
carbohydrates. This is discussed in greater detail in chapter 14.
The CKD: The ultimate solution?
To a great degree, the CKD avoids most of the problems discussed above. By allowing one
or more days of essentially ad-libitum eating, many of the above issues are eliminated. Monotony
is avoided since all food choices are allowed during the carb-up. Additionally, there can be some
consumption of fruits and vegetables during the carb-up. However, the CKD carries its own
particular problem for some people.
Many individuals see the carb-up as an ‘eat-anything day’ of their diet. Some individuals
have reported consuming upwards of 10,000 calories in a 24 hour time span during the carb-up, a
practice which is most likely unhealthy. In a sense, this makes the CKD look very much like a
binge-purge cycle with alternations of strict dieting with free-for-all eating. This may have the
potential to engender poor eating habits when the diet is ended. Ultimately, this is not different
from many fat-loss diets, especially those which are very restrictive.
Body composition issues
The primary selling point of the ketogenic diet is that it causes greater fat loss while
sparing protein losses. As discussed previously, this stance cannot be unequivocally defended
based on the data available. Anecdotally, many individuals find that fat loss is more effective and
that less muscle is lost with a ketogenic diet compared to more traditional dieting. This especially
applies to bodybuilders, who may be starting with far more muscle and less bodyfat, than the
average dieter. However this is not reported universally and most likely reflects differences in
individual physiology, insulin sensitivity, and other factors.
Additionally, many dieters are drawn to the ketogenic diet due to the rapid initial weight
loss which occurs from water loss. This is a double-edged sword. On the one hand, a rapid initial
drop in bodyweight can be psychologically very encouraging for individuals who have battled with
weight loss. By the same token, the rapid weight gain which can occur with even a small
carbohydrate intake can be just as psychologically devastating. Understanding the distinction
between weight loss and fat loss, as discussed in chapter 8, should help to avoid this problem.