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.

Circadian rhythms, gut microbiota, and diet: Possible implications for health.

AIMS: Over the past years, interest in chrono-nutrition has grown enormously as the fundamental role of circadian rhythms in regulating most physiological and metabolic processes has become clearer. Recently, the influence of circadian rhythms on the gut microbiota (GM) composition has also emerged, as more than half of the total microbial composition fluctuates rhythmically throughout the day. At the same time, other studies have observed that the GM itself synchronises the host's circadian biological clock through signals of a different nature. Therefore, it has been hypothesised that there is a two-way communication between the circadian rhythms of the host and the GM, but researchers have only just begun to identify some of its action mechanisms. The manuscript aim is, therefore, to gather and combine the latest evidence in the field of chrono-nutrition with the more recent research on the GM, in order to investigate their relationship and their potential impact on human health. DATA SYNTHESIS: Considering current evidence, a desynchronization of circadian rhythms is closely associated with an alteration in the abundance and functionality of the gut microbiota with consequent deleterious effects on health, such as increased risk of numerous pathologies, including cardiovascular disease, cancer, irritable bowel disease, and depression. A key role in maintaining the balance between circadian rhythms and GM seems to be attributed to meal-timing and diet quality, as well as to certain microbial metabolites, in particular short-chain fatty acids. CONCLUSIONS: Future studies are needed to decipher the link between the circadian rhythms and specific microbial patterns in relation to different disease frameworks.

Occurrence of Dysgeusia in Patients Being Treated for Cancer.

The aims of this study were to assess the presence of dysgeusia in patients receiving anticancer therapy and to explore possible factors influencing its occurrence. A total of 242 adult patients with histological diagnoses of malignant neoplasia and undergoing all types of anticancer treatment were included in the analysis. Data were collected from May 2019 to November 2019 at the Unit of Medical Oncology of Careggi University Hospital, Florence, Italy. Dysgeusia was assessed using the Chemotherapy-induced Taste Alteration Scale (CiTAS), while treatment-related symptoms were assessed using the Common Terminology Criteria for Adverse Events (CTCAE). Patients were aged 68 ± 13 years, mostly males (65%). A large proportion of them was undergoing chemotherapy (42.2%), while the others were receiving immunotherapy (20.7%), hormone therapy (15.5%), targeted therapy (12.8%), or a combination of them. Overall, 21.5% of patients reported dysgeusia, 17.4% nausea, 10.7% dysosmia, 9.9% xerostomia, 4.5% mucositis, and only 3.7% vomiting. The targeted therapy showed the greatest adverse effects, followed by chemotherapy, immunotherapy, and hormone therapy. When patients with dysgeusia were analyzed, phantogeusia and parageusia was the most affected dimension of gustatory disorders. Significant differences (p < 0.05) in CiTAS scores were found according to treatment-related symptoms for nausea and mucositis.

Morning chronotype is associated with higher adherence to the Mediterranean diet in a sample of Italian adults.

BACKGROUND AND AIMS: A growing body of evidence has associated subjects with an evening chronotype with worse eating behaviours and poorer diet quality. However, only few studies have investigated the relationship between chronotype and Mediterranean diet (MD). The aim of this study was to better understand the chronotype influence on dietary habits and MD adherence in a large sample of Italian adults. METHODS AND RESULTS: A total of 1247 participants (66.7% women) with a mean age of 36.1 ± 14.6 years were included in the analysis. Chronotype was classified as morning in 35.6% of subjects, intermediate in 56.7%, and evening in 7.1%. Regarding meal frequency, evening subjects showed a significantly (p < 0.05) greater tendency to skip breakfast (20.5%) than morning (6.9%) and intermediate (12%) subjects. Similarly, evening subjects were found to skip mid-morning snack more often than morning subjects (59.1% vs. 47.1%; p = 0.04), and lunch more often than intermediate subjects (8% vs. 2.8%; p = 0.01). In addition, all meals were eaten by evening subjects at a significantly delayed time, except for lunch. As to MD adherence a significant (p < 0.001) higher adherence in morning subjects (10.1 ± 2.2) compared to intermediate (9.5 ± 2.1) and evening (9.5 ± 2.2) subjects was observed. At a logistic regression analysis adjusted for possible confounding factors, morning subjects showed an increased probability (OR 1.54, 95%CI 1.19-1.99; p < 0.001) of being in the highest MD adherence tertile. CONCLUSION: Chronotype was associated with MD adherence. In particular, morning subjects showed higher MD adherence than intermediate and evening subjects.

Adherence to the Mediterranean diet increased during the COVID-19 lockdown in Italy: results from the web-based Medi-Lite questionnaire.

The aims of this study were to assess the Mediterranean Diet (MD) adherence in 2566 Italians who completed the validated Medi-Lite questionnaire during the year 2020, and to investigate the effect of COVID-19 confinement on dietary habits and MD adherence. To do this, we compared subjects (n = 389) that answered the questionnaire during the confinement occurred in Italy from March to May 2020 with subjects (n = 653) who completed the questionnaire in the same period (March-May) of the previous year (2019). From the results, a moderate level of MD adherence in the total sample emerged, and a significantly (p<.0001) increased adherence during lockdown was observed. Specifically, during confinement significantly (p < 0.05) higher consumption of vegetables (+9.4%), legumes (+13.5%) and pasta (+12.9%) emerged, while lower consumption was reported for bread (-13.4%) and meat and meat products (-15.4%). This study showed increased adherence to MD and a better-quality diet during the COVID-19 confinement in Italy.

Impaired Intracellular Ca2+ Dynamics, M-Band and Sarcomere Fragility in Skeletal Muscles of Obscurin KO Mice.

Obscurin is a giant sarcomeric protein expressed in striated muscles known to establish several interactions with other proteins of the sarcomere, but also with proteins of the sarcoplasmic reticulum and costameres. Here, we report experiments aiming to better understand the contribution of obscurin to skeletal muscle fibers, starting with a detailed characterization of the diaphragm muscle function, which we previously reported to be the most affected muscle in obscurin (Obscn) KO mice. Twitch and tetanus tension were not significantly different in the diaphragm of WT and Obscn KO mice, while the time to peak (TTP) and half relaxation time (HRT) were prolonged. Differences in force-frequency and force-velocity relationships and an enhanced fatigability are observed in an Obscn KO diaphragm with respect to WT controls. Voltage clamp experiments show that a sarcoplasmic reticulum's Ca2+ release and SERCA reuptake rates were decreased in muscle fibers from Obscn KO mice, suggesting that an impairment in intracellular Ca2+ dynamics could explain the observed differences in the TTP and HRT in the diaphragm. In partial contrast with previous observations, Obscn KO mice show a normal exercise tolerance, but fiber damage, the altered sarcomere ultrastructure and M-band disarray are still observed after intense exercise.

Effects of vegetarian versus Mediterranean diet on kidney function: Findings from the CARDIVEG study.

BACKGROUND: The aim of the present study was to assess the effects of a lacto-ovo-vegetarian diet (VD), compared to a Mediterranean diet (MD), on kidney function in a group of subjects with medium-to-low cardiovascular risk profile. METHODS: We analysed 107 subjects (82 women, 25 men; median age 52) who followed a VD (n = 54) and a MD (n = 53) for 3 months in the CARDIVEG study, a randomized, open, crossover trial that compared the effects of these 2 diets on cardiovascular disease risk. RESULTS: The effect of the two diets on kidney function markers was evaluated by conducting a general linear model for repeated measurements adjusted for possible confounding factors such as age, sex, physical activity, alcohol, smoking, hypertension, LDL cholesterol, glucose and body weight change. A significant reduction in creatinine (-5.3%; P < .001), urea nitrogen levels (-9%; P = .001), blood urea nitrogen (BUN) (-8.7%; P = .001) and BUN/creatinine ratio (-5.8%; P < .001), and an increase in estimated glomerular filtration rate (eGFR) (+3.5%; P = .001) was observed during the VD period. On the contrary, no significant changes were noted in the MD group. Variations obtained in the two dietary interventions were significantly different (P < .0001) for creatinine levels, BUN/creatinine and eGFR, for which opposite trends were observed in the VD and MD groups. CONCLUSIONS: In a selected group of subjects with medium-to-low cardiovascular risk profile, a 3 month VD period determined significant improvements in kidney function markers. Further trials are needed to confirm these results.

The relation between sarcomere energetics and the rate of isometric tension relaxation in healthy and diseased cardiac muscle.

Full muscle relaxation happens when [Ca2+] falls below the threshold for force activation. Several experimental models, from whole muscle organs and intact muscle down to skinned fibers, have been used to explore the cascade of kinetic events leading to mechanical relaxation. The use of single myofibrils together with fast solution switching techniques, has provided new information about the role of cross-bridge (CB) dissociation in the time course of isometric force decay. Myofibril's relaxation is biphasic starting with a slow seemingly linear phase, with a rate constant, slow kREL, followed by a fast mono-exponential phase. Sarcomeres remain isometric during the slow force decay that reflects CB detachment under isometric conditions while the final fast relaxation phase begins with a sudden give of few sarcomeres and is then dominated by intersarcomere dynamics. Based on a simple two-state model of the CB cycle, myofibril slow kREL represents the apparent forward rate with which CBs leave force generating states (gapp) under isometric conditions and correlates with the energy cost of tension generation (ATPase/tension ratio); in short slow kREL ~ gapp ~ tension cost. The validation of this relationship is obtained by simultaneously measuring maximal isometric force and ATP consumption in skinned myocardial strips that provide an unambiguous determination of the relation between contractile and energetic properties of the sarcomere. Thus, combining kinetic experiments in isolated myofibrils and mechanical and energetic measurements in multicellular cardiac strips, we are able to provide direct evidence for a positive linear correlation between myofibril isometric relaxation kinetics (slow kREL) and the energy cost of force production both measured in preparations from the same cardiac sample. This correlation remains true among different types of muscles with different ATPase activities and also when CB kinetics are altered by cardiomyopathy-related mutations. Sarcomeric mutations associated to hypertrophic cardiomyopathy (HCM), a primary cardiac disorder caused by mutations in genes encoding sarcomeric proteins, have been often found to accelerate CB turnover rate and increase the energy cost of myocardial contraction. Here we review data showing that faster CB detachment results in a proportional increase in the energetic cost of tension generation in heart samples from both HCM patients and mouse models of the disease.

Adherence to the Mediterranean diet among Italian adults: results from the web-based Medi-Lite questionnaire.

The adherence to the Mediterranean diet (MD) was assessed in a sample of 1820 non-selected individuals (1099 females and 721 males aged ≥18 years) who have completed the web version of the Medi-Lite score during the year 2019. Adherence to the MD was found to have a normal distribution and, on a scale from 0 to 18, the mean score was 12.2 ± 2.4. Significantly (p < 0.001) higher adherence scores were observed in females compared to males, in elderly people compared to young people, and in individuals with a university degree compared to those with a primary or a secondary school diploma. At the multivariate analysis, female gender, advanced age (>45 years), and higher education level were associated with a higher probability of being in the highest quartile of the Medi-Lite distribution. In conclusion, we found that some sub-groups of our population (males, younger individuals, and those with lower levels of education) need to improve their diet for reaching higher adherence scores to the MD.

Effect of consumption of ancient grain bread leavened with sourdough or with baker's yeast on cardio-metabolic risk parameters: a dietary intervention trial.

The aim of this study was to compare the effect of consumption of ancient grain "Verna" bread obtained by two different leavening agents, sourdough (SD) and baker's yeast (BY), on inflammatory parameters and cardiometabolic risk factors. Seventeen clinically healthy subjects were included to consume SD or BY bread for 4 weeks each, and blood analyses were carried out. The consumption of "Verna" bread obtained with both leavening agents led to a significant improvement of LDL cholesterol. A reduction of -10.6% and -8.53% was observed after replacement with SD and BY bread, respectively. A significant increase in fasting blood glucose (+6%) was observed only after the intervention with BY bread. A 10.7% decrease of vascular endothelial growth factor was found after the SD bread replacement period. The consumption of "Verna" bread resulted significantly associated with an improvement in the cardiometabolic and inflammatory profile. However, only consumption of BY bread determined a significant increase in blood glucose levels.

Effectiveness of a Khorasan Wheat-Based Replacement on Pain Symptoms and Quality of Life in Patients with Fibromyalgia.

OBJECTIVE: To investigate the effects of a replacement diet with Khorasan wheat products in patients with fibromyalgia, in comparison with a similar replacement diet with control products made from organic semi-whole-grain modern wheat. DESIGN: Randomized, double-blinded crossover trial. SETTING: Outpatient clinic. SUBJECTS: Twenty subjects (19 female and one male, mean age = 48.9 ± 12.3 years) with fibromyalgia. METHODS: Participants were randomly assigned to consume either Khorasan or control wheat products (pasta, bread, crackers, biscuits) for eight weeks and then crossed. Validated self-administered questionnaires were collected from each subject at the beginning and end of each intervention period. RESULTS: A general linear model for repeated measurement, adjusted for potential confounders, showed that the overall score reported from each questionnaire improved after both intervention and control periods, but the effect was more evident after the intervention with Khorasan. In particular, a statistically significant difference in Widespread Pain Index (WPI) + Severity Scale (SS) and Functional Outcome of Sleep Questionnaire (FOSQ) was observed, which decreased significantly by 21.5% and 11.7% respectively, only after the Khorasan period, while no statistically significant variations were reported after the control period. Similarly, FM Impact Questionnaire scores decreased significantly only after the Khorasan period, with a reduction that was significantly different between the intervention and control periods (-22.5% vs -0.3%, P = 0.037). The improvement was even greater in people with higher symptom severity. CONCLUSIONS: A dietary intervention with Khorasan wheat products seems to benefit patients with fibromyalgia, especially those with greater symptom severity.

Effects of a dietary intervention with Mediterranean and vegetarian diets on hormones that influence energy balance: results from the CARDIVEG study.

A randomised, open, crossover trial with two intervention periods was used to compare the effects of a 3-month dietary intervention with Mediterranean diet (MD) and vegetarian diet (VD) on hormones that influence energy balance, and to investigate the relationship with changes in body composition. After 3 months, no significant differences between the two diets were observed. Both MD and VD resulted in a significant (p < .05) reduction in leptin-to-adiponectin ratio and anthropometric parameters, MD resulted in a significant decrease in leptin levels (-7.4%), while VD determined a significant increase in adiponectin (+6.8%) and a significant decrease in visfatin (-12.7%) levels. In both groups, changes in leptin, insulin and HOMA-IR were significantly and positively correlated with changes in anthropometric parameters. In conclusion, both MD and VD have led to a slight but significant improvement in hormones that influence energy balance. The effect was more evident in participants who lost weight and fat mass.

Effects of Cutaneous Negative Pressure Application on Perforator Artery Flow in Healthy Volunteers: A Preliminary Study.

BACKGROUND: The creation of skin flaps based on small perforator vessels is an increasingly popular procedure nowadays; the optimization of their blood supply enhances surgical success. This study evaluates the effects on the flowmetries of 7 days' negative pressure application on the skin surface overlying the muscle fascia emergence of periumbilical perforators of the deep inferior epigastric artery (DIEA). METHODS: Ten volunteer participants were enrolled. In each subject, one periumbilical perforator of the DIEA was identified on each side of the abdomen using an eco-color-Doppler. One of them was used as the control group, while the other (the study group) underwent 80 mm Hg negative pressure for 7 days. The flowmetries of both perforators were measured before and after the application of negative pressure wound therapy. RESULTS: After the application of negative pressure, randomly applied on the skin surface over one of the two selected periumbilical perforators, an increase in the flowmetries was observed in both groups of perforators (2.74 cm/s; p < 0.0001). The relative flowmetry increase in the control group was 9.55% (2.735 cm/s), while in the study group it was 44.03% (8.748 cm/s). CONCLUSION: The application of negative pressure system on the skin surface over the muscle fascia emergence of the selected periumbilical perforators showed an increase in flowmetry. Although this is a preliminary study, this simple and economical procedure before surgery could be usefully employed to increase the rate of success in microsurgical procedures.

A Khorasan Wheat-Based Replacement Diet Improves Risk Profile of Patients With Nonalcoholic Fatty Liver Disease (NAFLD): A Randomized Clinical Trial.

OBJECTIVE: KAMUT khorasan is an ancient grain with widely acclaimed health benefits. The aim of this study was to investigate the effects of a replacement diet with ancient khorasan wheat products in patients with NAFLD, in comparison to a similar replacement diet with control products made from organic semi-whole-grain modern wheat. METHODS: Forty NAFLD patients (12 M/28 F; age 55.2 ± 10.4 years) with mild to moderate liver steatosis were included. The experimental design was a randomized, double-blind, parallel-arm study with 20 participants assigned to consume either KAMUT khorasan or control wheat products (pasta, bread, crackers, biscuits) over a 3-month period. Anthropometric measurements, blood analyses, and ultrasonography examination were performed at both the beginning and end of each dietary intervention. RESULTS: After the implementation of a general linear model for repeated measurements adjusted for baseline demographic details, risk factors, and medication, alanine aminotransferase (ALT) was significantly reduced by 12%, aspartate aminotransferase (AST) by 14%, alkaline phosphatase (ALP) by 8%, and cholesterol by 6% only in the khorasan group (p < 0.05 for all). Similarly, significant reductions in circulating proinflammatory tumor necrosis factor-alpha by 50%, interleukin l-receptor antagonist-alpha by 37%, interleukin-8 by 24%, and interferon gamma by 24% were evident only in participants who consumed the khorasan products (p < 0.05 for all). Finally, significant improvements in the liver steatosis grading, Doppler perfusion index values, and reactive oxygen species (ROS) production were evident after consumption of both the khorasan and control products. CONCLUSIONS: This study suggests that a short-term replacement diet with ancient KAMUT khorasan products is most effective in reducing metabolic risk factors and ameliorating the liver profile in patients with NAFLD.

Profiling Carbonylated Proteins in Heart and Skeletal Muscle Mitochondria from Trained and Untrained Mice.

Understanding the relationship between physical exercise, reactive oxygen species, and skeletal muscle modification is important in order to better identify the benefits or the damages that appropriate or inappropriate exercise can induce. Heart and skeletal muscles have a high density of mitochondria with robust energetic demands, and mitochondria plasticity has an important role in both the cardiovascular system and skeletal muscle responses. The aim of this study was to investigate the influence of regular physical activity on the oxidation profiles of mitochondrial proteins from heart and tibialis anterior muscles. To this end, we used the mouse as animal model. Mice were divided into two groups: untrained and regularly trained. The carbonylated protein pattern was studied by two-dimensional gel electrophoresis followed by Western blot with anti-dinitrophenyl hydrazone antibodies. Mass spectrometry analysis allowed the identification of several different protein oxidation sites, including methionine, cysteine, proline, and leucine residues. A large number of oxidized proteins were found in both untrained and trained animals. Moreover, mitochondria from skeletal muscles and heart showed almost the same carbonylation pattern. Interestingly, exercise training seems to increase the carbonylation level mainly of mitochondrial proteins from skeletal muscle.

Non-crossbridge stiffness in active muscle fibres.

Stretching of an activated skeletal muscle induces a transient tension increase followed by a period during which the tension remains elevated well above the isometric level at an almost constant value. This excess of tension in response to stretching has been called 'static tension' and attributed to an increase in fibre stiffness above the resting value, named 'static stiffness'. This observation was originally made, by our group, in frog intact muscle fibres and has been confirmed more recently, by us, in mammalian intact fibres. Following stimulation, fibre stiffness starts to increase during the latent period well before crossbridge force generation and it is present throughout the whole contraction in both single twitches and tetani. Static stiffness is dependent on sarcomere length in a different way from crossbridge force and is independent of stretching amplitude and velocity. Static stiffness follows a time course which is distinct from that of active force and very similar to the myoplasmic calcium concentration time course. We therefore hypothesize that static stiffness is due to a calcium-dependent stiffening of a non-crossbridge sarcomere structure, such as the titin filament. According to this hypothesis, titin, in addition to its well-recognized role in determining the muscle passive tension, could have a role during muscle activity.

Non-crossbridge forces in activated striated muscles: a titin dependent mechanism of regulation?

When skeletal muscles are stretched during activation in the absence of myosin-actin interactions, the force increases significantly. The force remains elevated throughout the activation period. The mechanism behind this non-crossbridge force, referred to as static tension, is unknown and generates debate in the literature. It has been suggested that the static tension is caused by Ca(2+)-induced changes in the properties of titin molecules that happens during activation and stretch, but a comprehensive evaluation of such possibility is still lacking. This paper reviews the general characteristics of the static tension, and evaluates the proposed mechanism by which titin may change the force upon stretch. Evidence is presented suggesting that an increase in intracellular Ca(2+) concentration leads to Ca(2+) binding to the PEVK region of titin. Such binding increases titin stiffness, which increases the overall sarcomere stiffness and causes the static tension. If this form of Ca(2+)-induced increase in titin stiffness is confirmed in future studies, it may have large implications for understating of the basic mechanisms of muscle contraction.

Force enhancement after stretch in mammalian muscle fiber: no evidence of cross-bridge involvement.

Stretching of activated skeletal muscles induces a force increase above the isometric level persisting after stretch, known as residual force enhancement (RFE). RFE has been extensively studied; nevertheless, its mechanism remains debated. Unlike previous RFE studies, here the excess of force after stretch, termed static tension (ST), was investigated with fast stretches (amplitude: 3-4% sarcomere length; duration: 0.6 ms) applied at low tension during the tetanus rise in fiber bundles from flexor digitorum brevis (FDB) mouse muscle at 30°C. ST was measured at sarcomere length between 2.6 and 4.4 µm in normal and N-benzyl-p-toluene sulphonamide (BTS)-added (10 µM) Tyrode solution. The results showed that ST has the same characteristics and it is equivalent to RFE. ST increased with sarcomere length, reached a peak at 3.5 µm, and decreased to zero at ∼4.5 µm. At 4 µm, where active force was zero, ST was still 50% of maximum. BTS reduced force by ∼75% but had almost no effect on ST. Following stimulation, ST developed earlier than force, with a time course similar to internal Ca(2+) concentration: it was present 1 ms after the stimulus, at zero active force, and peaked at ∼3-ms delay. At 2.7 µm, activation increased the passive sarcomere stiffness by a factor of ∼7 compared with the relaxed state All our data indicate that ST, or RFE, is independent of the cross-bridge presence and it is due to the Ca(2+)-induced stiffening of a sarcomeric structure identifiable with titin.

Effects of a dietary intervention with lacto-ovo-vegetarian and Mediterranean diets on apolipoproteins and inflammatory cytokines: results from the CARDIVEG study.

BACKGROUND: Apolipoproteins have been recently proposed as novel markers of cardiovascular disease (CVD) risk. However, evidence regarding effects of diet on apolipoproteins is limited. AIM: To compare the effects of Mediterranean diet (MD) and lacto-ovo vegetarian diet (VD) on apolipoproteins and traditional CVD risk factors in participants with low-to-moderate CVD risk. METHODS: Fifty-two participants (39 women; 49.1 ± 12.4 years), followed MD and VD for 3 months each. Medical and dietary information was collected at the baseline. Anthropometric parameters and blood samples were obtained at the beginning and the end of interventions. RESULTS: MD and VD resulted in significant improvement in anthropometric and lipid profiles. Both diets led to a reduction in most of the inflammatory parameters. As for apolipoproteins, a significant change was observed for ApoC-I after VD (+ 24.4%; p = 0.020). MD led to a negative correlation between ApoC-III and carbohydrates (R = - 0.29; p = 0.039) whereas VD between ApoD and saturated fats (R = - 0.38; p = 0.006). A positive correlation emerged after VD between HDL and ApoD (R = 0.33; p = 0.017) and after MD between plasma triglycerides and ApoC-I (R = 0.32; p = 0.020) and ApoD (R = 0.30; p = 0.031). IL-17 resulted to be positively correlated with ApoB after MD (R = 0.31; p = 0.028) and with ApoC-III after VD (R = 0.32; p = 0.019). Subgroup analysis revealed positive effects on apolipoproteins from both diets, especially in women, individuals older than 50 years-old or with < 3 CVD risk factors. CONCLUSIONS: Both diets seem to improve CVD risk, however, MD showed a greater positive effect on apolipoproteins in some subgroups, thus suggesting how diet may influence new potential markers of CVD risk. TRIAL REGISTRATION: registered at clinicaltrials.gov (identifier: NCT02641834) on December 2015.

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.