I am a scientist specialized on metabolism and genetics.


Abnormal eating behavior disrupts the circadian clock causing metabolic and psychiatric disorders.

In 10 seconds? Eating at the “wrong” time, or choosing the “wrong” food, causes a desynchronization of the internal clock, which may disrupt body physiology and metabolism. In the long run this leads to morning anorexia, evening hyperphagia, depressed mood, obesity and type 2 diabetes.

Don’t believe it? While the central clock controlling circadian rhythms, the suprachiasmatic nucleus in the hypothalamus, is mainly regulated by light, peripheral clocks are controlled by other factors, such as feeding/fasting. Thus, altered timing of food intake, or diets high on sugar or fat, can lead to uncoupling of peripheral clocks from the central pacemaker and is related to the development of metabolic and psychiatric disorders.

What kind of eating disorders are we talking about? The most frequent eating disorders leading to dysregulations of the internal clock are night eating, as in the Night Eating Disorder, or binge eating, when a person has recurrent episodes of eating large quantities of food rapidly. Also, unbalanced meals with too much sugar or too much fat, even during “correct” meal times, have been shown to alter the circadian clock. Although these disorders may be caused by genetic factors, they are mainly due to life style or stress.

How can we treat them? Several treatments exist for these eating disorders, such as improving the composition of meals, or controlling their timing. Bright light therapy can also be effective to improve eating behavior, as well as education and relaxation when the disorder is related to emotion or stress.


Time restricted feeding for prevention and treatment of cardiometabolic disorders.

Abstract: The soaring prevalence of obesity and diabetes is associated with an increase in comorbidities, including elevated risk for cardiovascular diseases (CVD). CVDs continue to be among the leading causes of death and disability in the United States. While increased nutrition intake from an energy dense diet is known to disrupt metabolic homeostasis and contributes to the disease risk, circadian rhythm disruption is emerging as a new risk factor for CVD. Circadian rhythms coordinate cardiovascular health via temporal control of organismal metabolism and physiology. Thus, interventions that improve circadian rhythms are prospective entry points to mitigate cardiometabolic disease risk. Although light is a strong modulator of neural circadian clock, time of food intake is emerging as a dominant agent that affects circadian clocks in metabolic organs. We discovered that imposing a time-restricted feeding (TRF) regimen in which all caloric intakes occur within a consistent ≤12 h every day exerts many cardiometabolic benefits. TRF prevents excessive body weight gain, improves sleep, and attenuates age- and diet- induced deterioration in cardiac performance. Using an integrative approach that combines Drosophila melanogaster (fruit fly) genetics with transcriptome analyses it was found that the beneficial effects of TRF are mediated by circadian clock, ATP dependent TCP/TRiC/CCT chaperonin and mitochondrial-ETC components. Parallel studies in rodents have shown TRF reduces cardiometabolic disease risks by maintaining metabolic homeostasis. As modern humans continue to live under extended periods of wakefulness and ingestion events, daily eating pattern offers a new potential target for lifestyle intervention to reduce CVD risk. This article is protected by copyright. All rights reserved.

Pub.: 16 Mar '17, Pinned: 28 Apr '17

A Systematic Review of Bright Light Therapy for Eating Disorders.

Abstract: Bright light therapy is a noninvasive biological intervention for disorders with nonnormative circadian features. Eating disorders, particularly those with binge-eating and night-eating features, have documented nonnormative circadian eating and mood patterns, suggesting that bright light therapy may be an efficacious stand-alone or adjunctive intervention. The purpose of this systematic literature review, using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, was (1) to evaluate the state of the empirical treatment outcome literature on bright light therapy for eating disorders and (2) to explore the timing of eating behavior, mood, and sleep-related symptom change so as to understand potential mechanisms of bright light therapy action in the context of eating disorder treatment.A comprehensive literature search using PsycInfo and PubMed/MEDLINE was conducted in April 2016 with no date restrictions to identify studies published using bright light therapy as a treatment for eating disorders. Keywords included combinations of terms describing disordered eating (eating disorder, anorexia nervosa, bulimia nervosa, binge eating, binge, eating behavior, eating, and night eating) and the use of bright light therapy (bright light therapy, light therapy, phototherapy). After excluding duplicates, 34 articles were reviewed for inclusion.14 published studies of bright light therapy for eating disorders met inclusion criteria (included participants with an eating disorder/disordered-eating behaviors; presented as a case study, case series, open-label clinical trial, or randomized/nonrandomized controlled trial; written in English; and published and available by the time of manuscript review).Results suggest that bright light therapy is potentially effective at improving both disordered-eating behavior and mood acutely, although the timing of symptom response and the duration of treatment effects remain unknown.Future research should systematically control for placebo response, assess symptom change frequently and across a broad range of systems, and evaluate the longer-term efficacy of bright light therapy for eating disorders.

Pub.: 12 Nov '16, Pinned: 28 Apr '17

Feeding during the resting phase causes profound changes in physiology and desynchronization between liver and muscle rhythms of rats.

Abstract: Shiftworkers run an increased risk of developing metabolic disorders, presumably as a result of disturbed circadian physiology. Eating at a time-of-day that is normally dedicated to resting and fasting, may contribute to this association. The hypothalamus is the key brain area that integrates different inputs, including environmental time information from the central biological clock in the suprachiasmatic nuclei, with peripheral information on energy status to maintain energy homeostasis. The orexin system within the lateral hypothalamus is an important output of the suprachiasmatic nuclei involved in the control of sleep/wake behavior and glucose homeostasis, among other functions. In this study, we tested the hypothesis that feeding during the rest period disturbs the orexin system as a possible underlying contributor to metabolic health problems. Male Wistar rats were exposed to an 8-week protocol in which food was available ad libitum for 24-hours, for 12-hours during the light phase (i.e., unnatural feeding time) or for 12-hours during the dark phase (i.e., restricted feeding, but at the natural time-of-day). Animals forced to eat at an unnatural time, i.e. during the light period, showed no changes in orexin and orexin-receptor gene expression in the hypothalamus, but the rhythmic expression of clock genes in the lateral hypothalamus was absent in these animals. Light fed animals did show adverse changes in whole body physiology and internal desynchronization of muscle and liver clock and metabolic gene expression. Eating at the 'wrong' time-of-day thus causes internal desynchronization at different levels, which in the long run may disrupt body physiology. This article is protected by copyright. All rights reserved.

Pub.: 27 Aug '16, Pinned: 28 Apr '17

Education, progressive muscle relaxation therapy, and exercise for the treatment of night eating syndrome. A pilot study.

Abstract: Night eating syndrome (NES) is a circadian rhythm disorder in which food intake is shifted toward the end of the day, interfering with sleep. According to the biobehavioral model of NES, the disorder is the result of a genetic predisposition that, coupled with stress, leads to enhanced reuptake of serotonin, thereby dysregulating circadian rhythms and decreasing satiety. Using the biobehavioral model as a guide, we developed a brief behavioral intervention using education, relaxation strategies, and exercise to address the core symptoms of NES. In this pilot randomized controlled clinical trial, 44 participants with NES were randomly assigned to an educational group (E; n = 14), E plus progressive muscle relaxation therapy (PMR; n = 15); or PMR plus exercise (PMR Plus, n = 15). Participants received a baseline intervention with 1- and 3-week follow-up sessions. Effectiveness analyses showed that participants in all three groups evidenced significant reductions on measures of NES symptoms (p < .001), depression (p < .05), anxiety (p < .01), and perceived stress (p < .05). However, the only significant between group change was for the percent of food eaten after the evening meal, with the PMR group showing the greatest reduction (-30.54%), followed by the PMR Plus group (-20.42%) and the E group (-9.5%); only the difference between the PMR and E groups was statistically significant (p = .012). Reductions in NES scores were significantly associated with reductions on measures of depression (r = .47; p < .01) and perceived stress (r = .37; p < .05), but not anxiety (r = .26, p = ns). Results support the role of education and relaxation in the behavioral treatment of NES.

Pub.: 11 Feb '15, Pinned: 28 Apr '17

Impact of nutrients on circadian rhythmicity.

Abstract: The suprachiasmatic nucleus (SCN) in the mammalian hypothalamus functions as an endogenous pacemaker that generates and maintains circadian rhythms throughout the body. Next to this central clock, peripheral oscillators exist in almost all mammalian tissues. Whereas the SCN is mainly entrained to the environment by light, peripheral clocks are entrained by various factors, of which feeding/fasting is the most important. Desynchronization between the central and peripheral clocks by, for instance, altered timing of food intake can lead to uncoupling of peripheral clocks from the central pacemaker and is, in humans, related to the development of metabolic disorders, including obesity and Type 2 diabetes. Diets high in fat or sugar have been shown to alter circadian clock function. This review discusses the recent findings concerning the influence of nutrients, in particular fatty acids and glucose, on behavioral and molecular circadian rhythms and will summarize critical studies describing putative mechanisms by which these nutrients are able to alter normal circadian rhythmicity, in the SCN, in non-SCN brain areas, as well as in peripheral organs. As the effects of fat and sugar on the clock could be through alterations in energy status, the role of specific nutrient sensors will be outlined, as well as the molecular studies linking these components to metabolism. Understanding the impact of specific macronutrients on the circadian clock will allow for guidance toward the composition and timing of meals optimal for physiological health, as well as putative therapeutic targets to regulate the molecular clock.

Pub.: 19 Dec '14, Pinned: 28 Apr '17

Characteristics and perspectives of night-eating behaviour in a severely obese population.

Abstract: Night-eating syndrome (NES) can be a feature of severe obesity. NES is a dysfunction of circadian rhythm and is associated with impaired sleep.Night eaters with severe obesity are more likely to be low in mood and unemployed compared with non-night eaters. Night eaters with severe obesity describe compulsive and uncontrolled eating. Research interest in night-eating syndrome (NES) has grown in recent years in line with increased rates of obesity. This study used a mixed-methods approach to investigate its characteristics in severe obesity. Eighty-one individuals (mean [standard deviation] age 44.6 [11.6] years, [body mass index] 50.0 [10.7] kg m(-2) ; 43% men) from a hospital-based UK obesity clinic were interviewed for NES based on 2003 criteria. Full and partial NES were combined into one night-eating behaviour (NEB) group (n = 31). Demographic and clinical characteristics were compared with those of non-NEB individuals (n = 50). NEB characteristics were also identified through exploratory thematic analysis of interview data. NEB individuals had lower mood (P = 0.01) and were less likely to be employed (P = 0.03). Differences in mean age and reported sleep duration were not significant. Thematic analysis of patient perceptions of NEB highlighted the potential heterogeneity of NEB development: NEB developed in childhood, adolescence and adulthood. Individuals reported long-standing and current sleep difficulties, negative affect and conflictful relationships. Night eating was solitary, compulsive and uncontrolled, and daytime eating patterns were chaotic. Accounts of awareness of night eating were conflicting. Severely obese night eaters are characterized by low mood and lack of employment. Further studies are required to explore behavioural and cognitive influences on night eating in severe obesity.

Pub.: 27 Nov '14, Pinned: 28 Apr '17