The keto diet—a revolution in weight loss or a dangerous fad?

Aim of the study: A ketogenic diet, characterized by low calories with high levels of fat, adequate levels of protein, and low levels of carbohydrates, has beneficial effects on body weight control in overweight patients. In the present study, a meta-analysis was conducted to investigate the role of a ketogenic diet in body weight control and glycemic management in overweight patients with type 2 diabetes mellitus (T2DM).

Results: In summary, we systematically reviewed articles from the Embase, PubMed, Web of Science and Cochrane Library databases and obtained eight randomized controlled trials for meta-analysis. The results show that a ketogenic diet had significantly beneficial effects on the loss of body weight (SMD, -5.63, p = 0.008), the reduction of waist circumference (SMD, -2.32, p = 0.04), lowering glycated hemoglobin (SMD, -0.38, p = 0.0008) and triglycerides (SMD, -0.36, p = 0.0001), and increasing high-density lipoproteins (SMD, 0.28, p = 0.003). Overall, these results suggest that a ketogenic diet may be an effective dietary intervention for body weight and glycemic control, as well as improved lipid profiles in overweight patients with T2DM. Hence, a ketogenic diet can be recommended for the therapeutic intervention of overweight patients with T2DM.

Aim of the study: The very low-calorie ketogenic diet (VLCKD) has been recently proposed as an appealing nutritional strategy for obesity management. The VLCKD is characterized by a low carbohydrate content (<50 g/day), 1-1.5 g of protein/kg of ideal body weight, 15-30 g of fat/day, and a daily intake of about 500-800 calories.

Results: Of the 645 articles retrieved, 15 studies met the inclusion criteria and were reviewed, revealing 4 main findings. First, the VLCKD was shown to result in a significant weight loss in the short, intermediate, and long terms and improvement in body composition parameters as well as glycemic and lipid profiles. Second, when compared with other weight loss interventions of the same duration, the VLCKD showed a major effect on reduction of body weight, fat mass, waist circumference, total cholesterol and triglyceridemia as well as improved insulin resistance. Third, although the VLCKD also resulted in a significant reduction of glycemia, HbA1c, and LDL cholesterol, these changes were similar to those obtained with other weight loss interventions. Finally, the VLCKD can be considered a safe nutritional approach under a health professional's supervision since the most common side effects are usually clinically mild and easily to manage and recovery is often spontaneous.

Aim of the study: Background/Objectives: Whether ketogenic diets provide greater weight-loss benefits than higher-carbohydrate diets when prescribed energy intake or targeted energy deficit are comparable remains uncertain. This systematic review and meta-analysis evaluated their effects on body weight change in adults with overweight or obesity.

Results: In three trials meeting the prescribed protein-matching criterion, the effect remained directionally consistent but was imprecise and compatible with no difference. Certainty of evidence was low because of risk of bias and imprecision. Conclusions: Under comparable prescribed energy conditions, ketogenic diets may produce a small additional reduction in body weight. However, predominantly short-term evidence, uncertainty regarding achieved energy and protein intakes, the absence of a synthesis of body composition, and low certainty of evidence limit confidence in the magnitude, durability, and clinical significance of this advantage.

Aim of the study: Studies evaluating the effects of novel, alternative dietary approaches for weight loss compared with the Mediterranean diet (MedDiet) are lacking. We aimed to evaluate the effects of diets with varying ketogenic potential, i.e., a very-low carbohydrate diet (ketogenic diet, KD), time-restricted eating (TRE), and modified alternate-day fasting (mADF) on weight loss in obesity, compared with a MedDiet.

Results: The mean age was 45.7 years (SD 10.7), and 70.6% were women. One hundred forty participants completed the study. Significant differences in weight loss from baseline to 3 months were found between KD and the control group [- 3.78 kg (- 5.65 to - 1.91 kg)], between mADF and the control group [- 3.14 kg (- 4.98 to - 1.30 kg)], and between lTRE and the control group [- 2.27 kg (- 4.13 to - 0.40 kg)], but not between eTRE and the control group [- 1.22 kg (- 3.07 to 0.64 kg)]. These results suggest that a calorie-restricted KD, mADF, or lTRE may be more effective for weight loss than a calorie-restricted MedDiet in obesity. Further research is needed to evaluate the long-term feasibility and efficacy of these dietary interventions compared with the MedDiet.

Aim of the study: Introduction: The ketogenic diet (KD) is widely used for weight management by reducing appetite, enhancing fat oxidation, and facilitating weight loss. However, the high content of total and saturated fats in a conventional KD may elevate low-density lipoprotein (LDL)-cholesterol levels, a known risk factor for cardiovascular diseases, highlighting the need for healthier alternatives.

Results: 0.6 ± 11.5 IU/L, p = 0.01)], with no increase in LDL-cholesterol (-0.12 ± 0.60 mmol/L vs. -0.04 ± 0.56 mmol/L, p = 0.97) observed in either group. Conclusions: The HKD was more effective than the ERD in promoting weight loss and improving cardiometabolic outcomes without elevation in LDL-cholesterol. It can be recommended for therapeutic intervention in patients with obesity.