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.

Nutrients. 2018;10(10)
Full text from:

Plain language summary

Obesity is a multi-factorial disorder involving genetic, environmental, metabolic and behavioural factors. Few studies have examined the effect of weight-loss therapy on various psychobiological parameters associated with obesity. Therefore the aim of this 4-month nutritional intervention was to evaluate food and alcohol cravings, physical activity levels, sleep quality, sexual function and quality of life in patients with obesity after following a very low-calorie ketogenic (VLCK) diet. Twenty obese patients were enrolled and participated in psychological questionnaires and anthropometric measurements at four points throughout the intervention: at baseline, maximum ketosis, reduced ketosis and endpoint. A specialist physician and expert dietician closely monitored participants to ensure safety and duration of the ketosis state. This study found that rapid and sustained weight loss induced by a VLCK-diet is associated with better food control and improvements in quality of life in obese subjects. Based on these results, the authors conclude a VLCK-diet is a suitable and valuable treatment option for 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.

Lifestyle medicine

Fundamental Clinical Imbalances : Hormonal ; Immune and inflammation
Patient Centred Factors : Mediators/Obesity
Environmental Inputs : Diet
Personal Lifestyle Factors : Nutrition ; Psychological
Functional Laboratory Testing : Blood ; Imaging
Bioactive Substances : Ketone bodies

Methodological quality

Allocation concealment : Not applicable


Nutrition Evidence keywords : Ketosis ; Very low-calorie ketogenic diet ; VLCK diet ; PNK method