Effect of a Very-Low-Calorie Ketogenic Diet on Circulating Myokine Levels Compared with the Effect of Bariatric Surgery or a Low-Calorie Diet in Patients with Obesity

: The preservation of muscle mass and muscle function after weight loss therapy is currently a considerable challenge in the fight against obesity. Muscle mass secretes proteins called myokines that have relevant functions in the regulation of metabolism and health. This study was aimed to evaluate whether a very low-calorie ketogenic (VLCK) diet may modulate myokine levels, in addition to changes in body composition, compared to a standard, balanced low-calorie (LC) diet or bariatric surgery in patients with obesity. Body composition, ketosis, insulin sensitivity and myokines were evaluated in 79 patients with overweight/obesity after a therapy to lose weight with a VLCK diet, a LC diet or bariatric surgery. The follow-up was 6 months. The weight loss therapies induced changes in myokine levels in association with changes in body composition and biochemical parameters. The effects on circulating myokine levels compared to those at baseline were stronger after the VLCK diet than LC diet or bariatric surgery. Differences reached statistical significance for IL-8, MMP2 and irisin. In conclusion, nutritional interventions or bariatric surgery to lose weight induces changes in circulating myokine levels, being this effect potentially most notable after following a VLCK diet.

Efficacy of very low-energy diet programs for weight loss: A systematic review with meta-analysis of intervention studies in children and adolescents with obesity

The objective of this review was to evaluate the efficacy and safety of very low-energy diet (VLED) programs for weight loss in children and adolescents with obesity. Six electronic databases were searched identifying 24 eligible studies (16 pre-post studies, four nonrandomized trials, two randomized controlled trials [RCTs], and two chart reviews) published up to October 2018. Studies were in English, implemented a VLED (≤3360 kJF/day [≤800 kcal/day] or <50% estimated energy requirements) in 5- to 18-year-olds with obesity, and reported at least one weight-related outcome. Weight-related outcomes significantly improved postintervention in all studies. Meta-analysis of 20 studies indicated a mean 10.1 kg (95% confidence interval [CI], 8.7-11.4 kg, P < 0.001; I²  = 92.3%) weight loss following interventions lasting 3 to 20 weeks. Moderator analysis indicated greater weight loss in adolescent-only studies (10-18 years) and formulated meal replacement interventions and inpatient settings. Meta-analysis of seven studies reporting weight at follow-up (5-14.5 months from baseline) indicated 5.3 kg mean weight loss (CI, 2.5-8.0 kg, P < 0.001; I²  = 50.6%). Details of adverse events were limited. VLED programs are effective for treating children and adolescents with obesity. However, conclusions on their safety cannot be drawn from the existing literature at this time. Future studies should include long-term follow-up with ongoing support and comprehensive monitoring of all adverse events.

Effect of A Very Low-Calorie Ketogenic Diet on Food and Alcohol Cravings, Physical and Sexual Activity, Sleep Disturbances, and Quality of Life in Obese Patients

Psychological well-being and hunger and food control are two relevant factors involved in the success of weight-loss therapy in treating obesity. Thus, this study aims to evaluate food and alcohol cravings, physical and sexual activity, sleep, and life quality (QoL) in obese patients following a very low-calorie ketogenic (VLCK) diet, as well as the role of weight lost and ketosis on these parameters. A battery of psychological test was performed in twenty obese patients (12 females, 47.2 ± 10.2 year and BMI of 35.5 ± 4.4) through the course of a 4-month VLCK diet on four subsequent visits: baseline, maximum ketosis, reduced ketosis, and endpoint. Each subject acted as their own control. Relevantly, the dietary-induced changes in body composition (7.7 units of BMI lost, 18 kg of fat mass (1.2 kg of visceral fat mass)) were associated with a statistically significant improvement in food craving scores, physical activity, sleepiness, and female sexual function. Overall, these results also translated in a notable enhancement in QoL of the treated obese patients. Therefore, the rapid and sustained weight and fat mass (FM) loss induced by the VLCK diet is associated with good food control and improvements in the psychological well-being parameters in obese subjects, which could contribute to the long-term success of this therapy.

Effect of a very low-energy diet on moderate and severe obstructive sleep apnoea: case reports

In this article, we report two cases from our study in which we investigated the effect of a very low-energy diet (VLED) for 9 weeks followed by a weight maintenance program for a total duration of 1 year in obese men with moderate to severe obstructive sleep apnea. The first case was a 43-year-old man with a body weight of 126 kg and a body mass index (BMI) of 38.8 kg/m(2) at baseline. Over the 1-year treatment program he lost 26% of his initial weight and his apnea-hypopnea index (AHI) was improved by 60%. The second case was at baseline a 54-year-old man with a weight of 87 kg and BMI of 32.1 kg/m(2) . Over the 1-year treatment program he lost 10% of his initial weight and his AHI improved by 66%. In summary, treatment with a VLED followed by a weight maintenance program significantly improved obstructive sleep apnea in both cases.