Effects of a chronotype-adapted diet on weight loss, cardiometabolic health, and gut microbiota: study protocol for a randomized controlled trial.

BACKGROUND: Obesity and its associated health complications have become a global public health concern, necessitating innovative approaches to weight management. One emerging area of research focuses on the influence of chronotype, an individual's preferred timing for daily activities, on eating habits, weight regulation, and metabolic health. Recent observational studies suggest that the misalignment between an individual's chronotype and external cues, such as meal timing, may contribute to metabolic dysregulation and obesity, but evidence from intervention studies is still limited. This study protocol describes a randomized controlled trial designed to explore the effects of a chronotype-adapted diet, compared with a diet with a conventional calorie distribution, on weight loss, cardiometabolic health, and gut microbiota composition. METHODS: A total of 150 overweight/obese adults will be recruited for this 4-month parallel-group, randomized, two-arm, open-label, superiority trial with 1:1 allocation ratio. Participants will be randomly assigned to either the intervention group or the control group. The intervention group will receive a low-calorie chronotype-adapted diet with a calorie distribution adapted to the individual chronotype (morning or evening), optimizing meal timing according to their peak metabolic periods. The control group will follow a standardized low-calorie healthy eating plan without considering chronotype. Both diets will have equivalent daily calorie content, adjusted according to gender and starting weight. Anthropometric measurements, body composition, blood, and fecal samples will be obtained from each participant at the beginning and the end of the study. The primary outcome is weight change from baseline. Secondary outcomes are changes from baseline in body mass index (BMI), fat mass, lipid and glycemic profile, fecal microbiota profile, and short-chain fatty acids (SCFAs). DISCUSSION: The results of this randomized controlled trial have the potential to advance our understanding of the complex interactions between chronotype, diet, body weight, and health outcomes. By providing evidence for personalized dietary interventions based on individuals' circadian preferences, this research could offer insights into personalized nutrition strategies. Such knowledge could guide the development of innovative dietary interventions to optimize the prevention and management of overweight and obesity, while also improving the risk profile of these individuals. TRIAL REGISTRATION: ClinicalTrials.gov NCT05941871. Registered on 18 May 2023.

Assessment of Mediterranean diet adherence and comparison with Italian dietary guidelines: a study of over 10,000 adults from 2019 to 2022.

Despite the many well-documented benefits of the Mediterranean diet (MD), many Mediterranean countries seem to be moving away from it. The aim of this study was to investigate the MD adherence in 10,916 adults who completed the validated Medi-Lite questionnaire from January 2019 to December 2022 in Italy, and to assess the consumption of its food groups by comparing them with current national dietary guidelines. The sample showed a good level of MD adherence (12 ± 2.5). However, from 2019 to 2022, a significant (p < 0.001) decline in the adherence level emerged. An overconsumption of fresh red meat, cheese and poultry compared to dietary guidelines was observed. In contrast, an under-consumption of vegetables, bread, legumes, fish and milk and dairy products emerged. In recent years, a decline in MD adherence was observed in Italy, probably determined by an excessive consumption of animal products.

Low-Grade Inflammation and Ultra-Processed Foods Consumption: A Review.

Low-grade inflammation alters the homeostasis of the organism and favors the onset of many chronic diseases. The global growth in the prevalence of noncommunicable diseases in recent years has been accompanied by an increase in the consumption of ultra-processed foods (UPF). Known to be hyperpalatable, economic and ready-to-eat, increased consumption of UPF has already been recognized as a risk factor for several chronic diseases. Different research groups have tried to investigate whether UPF consumption could promote low-grade inflammation and thus favor the development of noncommunicable diseases. Current evidence highlights the adverse health effects of UPF characteristics, not only due to the nutrients provided by a diet rich in UPF, but also due to the non-nutritive components present in UPF and the effect they may have on gut health. This review aims to summarize the available evidence on the possible relationship between excessive UPF consumption and modulation of low-grade inflammation, as potential promoters of chronic disease.

Association between Psychological Disorders, Mediterranean Diet, and Chronotype in a Group of Italian Adults.

Mental health conditions are a significant contributor to the global burden of disease. The aim of this study was to explore the association between psychological disorders, Mediterranean diet (MD), and chronotype. A total of 344 participants (74% women) with a mean age of 33.5 ± 13 years were recruited. According to the Depression Anxiety Stress Scale (DASS-21) score, 22% of participants had symptoms of depression, 23% anxiety, and 10% stress. The assessment of MD adherence through the Medi-Lite score revealed that participants with psychological disorders had significantly (p < 0.05) lower MD adherence than those without these conditions. Furthermore, less than 10% of the subjects with at least one symptom reported consuming the optimal amount of fruit and vegetables, while 72% showed excessive consumption of meat and meat products. Regarding chronotype, evening subjects reported the lowest MD adherence and the highest prevalence of all three psychological disorders analyzed. A multivariate analysis showed that female gender, age, being unmarried/single, sedentary lifestyle, and low MD adherence were associated with a significantly higher risk of depression, anxiety, and stress. Future studies are needed to explore the relationship between mental health and risk factors to improve personal and global population health.