Melatonin, a hormone secreted by the body, helps control weight gain by stimulating the appearance of ‘beige fat’ that can burn calories instead of storing them, according to new research from Spanish scientists.

Meanwhile, a study from Temple University has found that getting enough sleep could be the key to regulating appetite in children.

Melatonin stimulates ‘beige fat’

Melatonin is a natural hormone segregated by the body. Levels of the hormone generally increase in the dark at night, but it is also found in fruits and vegetables like mustard, goji berries, almonds, sunflower seeds, cardamom, fennel, coriander and cherries.

In a study published recently in the Journal of Pineal Research, scientists from the University of Granad Institute for Neuroscience, the Hospital Carlos III, Madrid, and the University of Texas Health Science Centre in San Antonio (US) showed that consumption of melatonin stimulates the appearance of ‘beige fat’, thereby helping to control weight gain. ‘Beige fat’ burns calories in vivo instead of storing. White adipose tissue, however, stores calories, leading to weight gain.

The researchers said their findings show that melatonin has metabolic benefits in treating diabetes and hyperlipidemia.

Melatonin increases ‘beige fat’ in obese and thin rats

In earlier publications, the researchers analysed the effects of melatonin on obesity, dyslipidemia, high blood pressure and type 2 diabetes associated with obesity in young obese diabetic Zucker rats — an experimental model of metabolic syndrome.

In view of their most recent results, the researchers said it seemed the key lies in the fact that chronic melatonin consumption not only induces the appearance of ‘beige fat’ in obese diabetic rats, but also increases its presence in thin animals used as a control group. ‘Beige fat’ cells are found in scattered lentil-sized deposits beneath the inguinal skin in obese diabetic Zucker rats.

Potential treatment for obesity, researchers

Melatonin is a natural hormone segregated by the human body itself and melatonin levels generally increase in the dark at night. It is also found in small quantities in fruit and vegetables like mustard, Goji berries, almonds, sunflower seeds, cardamom, fennel, coriander and cherries.

Researchers said these findings, together with the pharmacologically safe profile of melatonin, mean it is a potentially useful tool both in its own right and to complement the treatment of obesity. Sleeping in the dark and consuming these foodstuffs could help control weight gain and prevent cardiovascular diseases associated with obesity and dyslipidemia.

The researchers said the study—coordinated by University of Granada lecturer Ahmad Agil—showed that chronic administration of melatonin sensitizes the thermogenic effect of exposure to cold, heightens the thermogenic effect of exercise and, therefore, constitutes excellent therapy against obesity. Researchers said one of the key differences between ‘beige fat’, which appears when administering melatonin, and ‘white fat’, is that ‘beige fat’ cell mitochondria express levels of UCP1 protein, responsible for burning calories and generating heat.

The study—authored by Aroa Jiménez-Aranda, Gumersindo Fernández-Vázquez, Daniel Campos, Mohamed Tassi, Lourdes Velasco-Perez, Tx Tan, Russel J. Reiter and Ahmad Agil—was been part-financed and supported by the Granada Research of Excellence Initiative on BioHealth (GREIB), the University of Granada Vice-Rectorate for Scientific Policy and Research, and the regional government of Andalusia research group CTS-109.

Kids who sleep more may eat less

Fast food, sugary drinks and large portion sizes have all taken heat as possible causes of childhood obesity, but getting enough sleep may be the key to regulating appetite, according to a new study from Temple University.

The study, published 4 November 2013 in the journal Pediatrics, found that children who increased their sleep time reported consuming an average of 134 fewer calories per day, weighed half a pound less and had lower fasting levels of leptin, a hunger-regulating hormone that is also highly correlated with the amount of adipose tissue, when compared to the week of decreased sleep.

“Findings from this study suggest that enhancing school-age children’s sleep at night could have important implications for prevention and treatment of obesity,” said Chantelle Hart, Associate Professor of Public Health at Temple University’s Centre for Obesity Research and Education (CORE). “The potential role of sleep should be further explored,” she said.

Study method

The study, which was conducted while Dr. Hart was at the Miriam Hospital and Alpert Medical School of Brown University, involved 37 children, ages 8 to 11; 27 percent of whom were overweight or obese.

For the first week of the study, children were asked to sleep their typical amount. Next, during the second week, the group was randomized to either reduce or lengthen their sleep time; participants completed the opposite sleep schedule during the third and final week of the study.

Professor Hart is now working on a study funded by the National Heart Lung and Blood Institute of the NIH using a brief behavioral intervention to get kids to increase their sleep to determine if there are significant changes in eating, activity behaviors and weight status.

“Given all of its documented benefits, in many ways, you can’t lose in promoting a good night’s sleep,” Professor Hart said.

Funding for this research was provided by a grant from the American Diabetes Association.