In the past decades, dietary guidelines focused on reducing saturated fat as the primary strategy for
cardiovascular disease prevention, neglecting the many other potential effects of diet on health, in particular the harmful effects of
sugar. A greater intake of soft drinks (sugar-sweetened beverages), for example, is associated with a 44% increased prevalence of
metabolic syndrome, a higher risk of
obesity, and a 26% increased risk of developing
diabetes mellitus.
Carbohydrates comprise around 55% of the typical western diet, ranging from 200 to 350 g/day in relation to a person's overall caloric intake. For long-term
weight gain, food rich in refined grains, starches, and
sugar appear to be major culprits.
Low-carbohydrate diets restrict daily
carbohydrates between 20 and 50 g, as in clinical
ketogenic diets. The results of controlled trials show that people on
ketogenic diets (a diet with no more than 50 g
carbohydrates/day) tend to lose more weight than people on
low-fat diets. Moreover, there is no good evidence for recommending
low-fat diets, as
low-carbohydrate diets lead to significantly greater
weight loss (1.15 kg) than did low-fat interventions. However, the magnitude of such a benefit is small. As the quality of ingested
carbohydrates seems more important than the quantity for health outcomes, people with metabolic disorders should avoid or substantially reduce low-fiber, rapidly digested, refined grains, starches, and added
sugars. So, the consumption of the right
carbohydrates (high-fiber, slowly digested, and whole grains), in a moderately lower amount (between 40 and 50% of daily energy content), is compatible with a state of good health and may represent a scientifically-based and palatable choice for people with metabolic disorders.