Conclusions
Reducing CHO intake with an LCD is effective in reducing body weight and, in patients with
type 2 diabetes, improving glycemic control, with a stronger effect with a very low carb diet (KD).
However, LCD and KD may not be appropriate for all individuals. Especially in patients with type 2
diabetes, it is necessary to balance the potential increase in cardiovascular risk because of the
unfavorable lipid profile observed with KD with the benefits deriving from weight loss and
improvement of glycemic control. Moreover, long-term compliance with low-CHO diets is still an
issue.
In type 1 diabetes, there is no present evidence that an LCD or a KD can delay or prevent the
onset of the disease. These diets have the potential to improve metabolic control, but caution is
needed because of the risk of DKA, of worsening the lipid profile and, in children, the unknown
impact on growth.
Even in studies in the general population where a higher CHO intake was associated with
worse outcomes, healthier macronutrients consumption was associated with decreased
cardiovascular and non-cardiovascular mortality. When healthy LFD was compared to healthy LCD,
good results in terms of weight loss were observed with both diets. Therefore, macronutrients
source, i.e., CHO quality, are not negligible factors, and preferring fibers and nutrient-rich foods is a
good option for everyone. For this reason, when designing future studies on nutrition, it will be
important to evaluate not only the amount of CHO, but also their type.
Even though this review is not about exercise, we want to underline in the conclusion that diet
and exercise are both vitally important to good health in diabetes. All the exercise in the world will
not help you lose weight if your nutrition levels are out of control, but the adoption and maintenance of
physical activity are critical foci for blood glucose management and overall health in individuals
with diabetes and prediabetes. In this direction, we reported the conclusion of the recent position
statement of the American Diabetes Association [103]: “Physical activity and exercise should be
recommended and prescribed to all individuals with diabetes as part of management of glycemic
control and overall health. Specific recommendations and precautions will vary by the type of
diabetes, age, activity done, and presence of diabetes-related health complications.
Recommendations should be tailored to meet the specific needs of each individual...”.
In conclusion, LCD and KD can be effective options in patients with obesity and/or type 2
diabetes, although they are not the only available dietary approach for such patients. In any diet,
LCD and KD should be tailored to individual needs and patients should be followed for an extended
period of time. The use of those diets in patients with type 1 diabetes is still controversial and their
long-term safety is still unproven.
Further large-scale, long-term, well-designed randomized trials are needed on this topic to
assess the long-term safety, efficacy and compliance of reducing dietary CHO in patients with
diabetes, and particularly with type 1 diabetes of all ages, and to find the best dietary composition as
for glycemic control, weight loss, and CV risk in all patients with diabetes.