Cutting calories can help sleep apnea

Obese adults eating fewer calories can have positive effects on sleep apnea and blood pressure.

A recent study conducted by Brazilian researchers reported that consuming fewer calories could improve sleep apnea and lower blood pressure in obese adults.

Sleep apnea is a potentially serious sleep disorder in which breathing stops and starts during sleep. Additionally, the disorder is associated with high blood pressure, heart problems, and stroke.

The Brazilian study involved 21 obese adults, between 20 and 55 years old, with sleep apnea. Some of the 21 adults reduced their caloric intake by 800 calories over a 16-week period, while the remaining made no changes to their diet.

At the study’s end, investigators found that those who reduced calories had lower blood pressure, had lost more weight, had fewer breathing issues during sleep, and had higher amounts of oxygen in their blood.

Findings of the study were announced at the American Heart Association high blood pressure meeting in San Francisco last week. Data and research presented at medical seminars is deemed inconclusive unit it is published in a peer-reviewed journal.

Dr. Marcia Klein, study co-author and adjunct professor at the University of Rio de Janero State University in Brazil, said the study’s findings reveal that moderate energy restriction in obese adults can improve sleep apnea, as well as blood pressure and heart rate.

Even a slight energy restriction, said Klein, can improve an obese adult’s entire cardiovascular system.

Klein also said that losing weight through dieting and exercise should remain the number one combative against sleep apnea. As a result, systolic blood pressure is often lowered by weight reduction.

Systolic blood pressure is the top number in a blood pressure reading that reflects the force of blood in the arteries when the heart beats. The bottom number in a reading, diastolic blood pressure, measures pressures in the arteries between heart beats. A good blood pressure reading is considered to be below 120/80 mm Hg.

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Food purchasing is increased after sleep deprivation

A study links sleep deprivation to purchasing more food the following day which could influence weight gain and obesity over time.

People who were deprived of one night's sleep purchased more calories and grams of food in a mock supermarket on the following day in a new study published in the journal Obesity, the official journal of The Obesity Society. Sleep deprivation also led to increased blood levels of ghrelin, a hormone that increases hunger, on the following morning; however, there was no correlation between individual ghrelin levels and food purchasing, suggesting that other mechanisms -- such as impulsive decision making -- may be more responsible for increased purchasing.

Researchers in Sweden were curious as to whether sleep deprivation may impair or alter an individual's food purchasing choices based on its established tendency to impair higher-level thinking and to increase hunger.

"We hypothesized that sleep deprivation's impact on hunger and decision making would make for the 'perfect storm' with regard to shopping and food purchasing -- leaving individuals hungrier and less capable of employing self-control and higher-level decision-making processes to avoid making impulsive, calorie-driven purchases," said first author Colin Chapman, MSc, of Uppsala University.

On the morning after one night of total sleep deprivation, as well as after one night of sleep, Chapman, along with Christian Benedict, PhD, and their colleagues, gave 14 normal-weight men a fixed budget (approximately $50). The men were instructed to purchase as much as they could out of a possible 40 items, including 20 high-caloric foods and 20 low-calorie foods. The prices of the high-caloric foods were then varied to determine if total sleep deprivation affects the flexibility of food purchasing. Before the task, participants received a standardized breakfast to minimize the effect of hunger on their purchases.

Sleep-deprived men purchased significantly more calories (+9%) and grams (+18%) of food than they did after one night of sleep. The researchers also measured blood levels of ghrelin, finding that the hormone's concentrations were higher after total sleep deprivation; however, this increase did not correlate with food purchasing behavior.

"Our finding provides a strong rationale for suggesting that patients with concerns regarding caloric intake and weight gain maintain a healthy, normal sleep schedule," said Chapman.

Follow up studies are needed to address whether these sleep deprivation-induced changes in food purchasing behavior also exist under partial sleep deprivation, though. Additional research should also look into sleep deprivation's potential impact on purchasing behavior in general, as it may lead to impaired or impulsive purchasing in a variety of other contexts.

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What causes late-night snack cravings?

This article discusses a study on the circadian rhythm and how it influences certain cravings late at night.

A study published in the most recent version of the journal Obesity found that the body's internal clock, the circadian system, increases hunger and cravings for sweet, starchy and salty foods in the evenings. While the urge to consume more in the evening may have helped our ancestors store energy to survive longer in times of food scarcity, in the current environment of high-calorie food, those late night snacks may result in significant weight gain.

"Of course, there are many factors that affect weight gain, principally diet and exercise, but the time of eating also has an effect. We found with this study that the internal circadian system also likely plays a role in today's obesity epidemic because it intensifies hunger at night," said Steven Shea, Ph.D., director for the Center for Research on Occupational and Environmental Toxicology at Oregon Health & Science University and senior author on the study. "People who eat a lot in the evening, especially high-calorie foods and beverages, are more likely to be overweight or obese."

Indeed, eating a lot in the evening can be counterproductive since the human body handles nutrients differently depending on the time of day. For example, sugar tolerance is impaired in the evening. Additionally, consuming more calories in the evening predisposes people to more energy storage; we simply don't expend as much energy after an evening meal in comparison to morning meals.

Furthermore, artificial light enables people to stay up later than they probably should and often people don't get enough sleep. "If you stay up later, during a time when you're hungrier for high-calorie foods, you're more likely to eat during that time," Shea said. "You then store energy and get less sleep, both of which contribute to weight gain."

"If weight loss is a goal, it's probably better to eat your larger, higher-calorie meals earlier in the day," said Shea. "Knowing how your body operates will help you make better choices. Going to bed earlier, getting enough sleep and choosing lower-calorie foods rather than higher-calorie foods in the evening can all help with weight loss."

Conducted by Shea and two Boston-area researchers, Frank Scheer, Ph.D. and Christopher Morris, Ph.D. of Brigham and Women's Hospital and Harvard Medical School, the study examined the appetite and food preference of 12 healthy non-obese adults throughout a 13-day laboratory stay in very dim light in which all behaviors were scheduled, including timing of meals and sleep. Dr. Scheer, first author on the study, explained that "by the end of this long protocol, all of the participants' meals and activities were spaced evenly across the day and night, allowing examination of the true internal circadian effects on appetite, while controlling for other effects on appetite including the amount of food recently consumed."

The researchers found that the internal circadian system regulated hunger, with participants feeling the least hungry in the morning (8 a.m.) and most hungry in the evening (8 p.m.). Similar rhythms were found in appetite for types of food, such as sweet, starchy and salty, and the estimate of how much food participants could eat. The study concludes that the internal circadian system causes an evening peak in appetite that may promote larger, higher-calorie meals before the fasting period necessitated by sleep.

"Our study suggests that because of the internal circadian regulation of appetite, we have a natural tendency to skip breakfast in favor of larger meals in the evening. This pattern of food intake across the day is exactly what Sumo wrestlers do to gain weight." said Steven Shea. "So, it seems likely that the internal circadian system helps with efficient food storage. While this may have been valuable throughout evolution, nowadays it is likely to contribute to the national epidemic of obesity."

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Link Between Lack of Sleep and Junk Food Binging

Lack of sleep can result in a person eating greater quantities of high-calorie junk food resulting in weight gain over time

Lack of sleep can lead you to eat larger portions of high-calorie foods and increase your long-term risk of weight gain, according to a small new study.

Swedish researchers asked 16 normal-weight males to choose their ideal portions of high-calorie meals and snacks. They did this when they had a normal night of about eight hours sleep and again when they went a night without sleep.

The participants chose larger portion sizes after the night with no sleep. They did this both before and after a breakfast, which suggests that sleep deprivation increases food intake regardless of whether a person feels full, said study author Pleunie Hogenkamp, of Uppsala University.

"Bearing in mind that insufficient sleep is a growing problem in modern society, our results may explain why poor sleep habits can affect people's risk to gain weight in the long run," Hogenkamp said in a university news release.

The study was published online Feb. 18 in the journal Psychoneuroendocrinology.

In a previous study, the same team of researchers found that young, normal-weight men who went a single night without sleep had increased activation of a brain region involved in the desire to eat.

Although the study found an association between lack of sleep and increased appetite for high-calorie foods, it did not prove a cause-and-effect relationship.

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Autistic Children at Risk for Feeding Issues and Nutritional Deficits

A study on the nutritional habits of children with Autism shows that Autistic children are much more likely to have a feeding problem which may result in decreased growth.

Healthy eating not only promotes growth and development, but also provides important opportunities for children to socialize during meals. A new, comprehensive analysis of feeding behavior in children with autism spectrum disorders (ASD) indicates that these children are five times more likely to have a feeding problem, including extreme tantrums during meals, severe food selectivity and ritualistic mealtime behaviors.

Researchers at Marcus Autism Center and the Department of Pediatrics at Emory University School of Medicine conducted a comprehensive meta-analysis of all published, peer-reviewed research relating to feeding problems and autism. Examination of dietary nutrients showed significantly lower intake of calcium and protein and a higher number of nutritional deficits overall among children with autism.

The results are reported in the Feb. 1, 2013, online early edition of theJournal of Autism and Developmental Disorders.

"The results of this study have broad implications for children with autism," says William Sharp, PhD, a behavioral pediatric psychologist in the Pediatric Feeding Disorders Program at Marcus Autism Center and assistant professor at Emory University School of Medicine. "It not only highlights the importance of assessing mealtime concerns as part of routine health care screenings, but also suggests the need for greater focus on diet and nutrition in the autism community."

Chronic feeding problems increase a child's risk for poor medical and developmental outcomes, including malnutrition, growth retardation, social deficits and poor academic achievement. Emerging evidence suggests the feeding problems and dietary patterns associated with autism may place this population at risk for long-term medical complications, including poor bone growth, obesity and other diet-related diseases (e.g., cardiovascular disease) in adolescence or adulthood.

While parents of children with autism frequently express concern regarding how few foods make up their child's diet, the systematic review and meta-analysis led by Sharp and colleagues represents the first attempt to combine outcomes from studies providing empirical evidence about levels of feeding problems and nutrient intake in children with autism compared with peers.

"Despite the risk of long-term medical issues, as well as frequent caregiver concern regarding the quality of their child's diet, feeding problems are often overlooked in relation to other areas of clinical and research concern in the autism population," says Sharp.

"Our findings have immediate and important implications for the work of practitioners serving children and families with autism, who in the absence of such information, may struggle to address parents' concerns, or, worse, may fill the void with alternative treatments that may be ill-conceived or even harmful to children and families."

One important example is the highly prevalent adoption of elimination diets as a form of treatment for autism, which, the data appear to suggest, could further exacerbate the nutritional risks for children with autism. With this in mind, Sharp and colleagues used this information to develop autism-specific recommendations to guide future clinical and research activities in this area.

These recommendations included screening for feeding concerns and nutritional deficits/excesses in addition to measurement of gross anthropometric parameters as part of routine medical evaluations for children with ASD. They also suggest healthcare providers review the potential consequences of pursuing an elimination diet with consideration of the child's unique feeding and nutritional presentation.

"This study is the first of its kind to quantify the impact of feeding disorders in the autism population," says Sharp. "We hope that our work helps guide clinical practice, as well as provides a roadmap for future research in this area."

Now that the magnitude of the feeding disorders in the autism population has been defined, Marcus Autism Center is now using these findings to expand the research program for children with autism and feeding disorders seen through its Pediatric Feeding Disorders Program.

Future areas of research include the more detailed analysis of the health burden associated with atypical dietary patterns, such as prevalence of obesity and obesity related disorders, as well as determining the social implications and family stress associated with chronic feeding problems in this population.

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Excess holiday eating has same effect as jet lag

This article discusses how excess holiday eating disturbs your "food clock" and has effects similar to jet lag or working the graveyard overnight shift at work. It also discusses how to reset your "food clock."

If the sinful excess of holiday eating sends your system into butter-slathered, brandy-soaked overload, you are not alone: People who are jet-lagged, people who work graveyard shifts and plain-old late-night snackers know just how you feel.

All these activities upset the body's "food clock," a collection of interacting genes and molecules known technically as the food-entrainable oscillator, which keeps the human body on a metabolic even keel. A new study by researchers at the University of California, San Francisco (UCSF) is helping to reveal how this clock works on a molecular level.

Published this month in the journalProceedings of the National Academy of Sciences, the UCSF team has shown that a protein called PKCγ is critical in resetting the food clock if our eating habits change.

The study showed that normal laboratory mice given food only during their regular sleeping hours will adjust their food clock over time and begin to wake up from their slumber, and run around in anticipation of their new mealtime. But mice lacking the PKCγ gene are not able to respond to changes in their meal time -- instead sleeping right through it.

The work has implications for understanding the molecular basis of diabetes, obesity and other metabolic syndromes because a desynchronized food clock may serve as part of the pathology underlying these disorders, said Louis Ptacek, MD, the John C. Coleman Distinguished Professor of Neurology at UCSF and a Howard Hughes Medical Institute Investigator.

It may also help explain why night owls are more likely to be obese than morning larks, Ptacek said.

"Understanding the molecular mechanism of how eating at the "wrong" time of the day desynchronizes the clocks in our body can facilitate the development of better treatments for disorders associated with night-eating syndrome, shift work and jet lag," he added.

Resetting the Food Clock

Look behind the face of a mechanical clock and you will see a dizzying array of cogs, flywheels, reciprocating counterbalances and other moving parts. Biological clocks are equally complex, composed of multiple interacting genes that turn on or off in an orchestrated way to keep time during the day.

In most organisms, biological clockworks are governed by a master clock, referred to as the "circadian oscillator," which keeps track of time and coordinates our biological processes with the rhythm of a 24-hour cycle of day and night.

Life forms as diverse as humans, mice and mustard greens all possess such master clocks. And in the last decade or so, scientists have uncovered many of their inner workings, uncovering many of the genes whose cycles are tied to the clock and discovering how in mammals it is controlled by a tiny spot in the brain known as the "superchiasmatic nucleus."

Scientists also know that in addition to the master clock, our bodies have other clocks operating in parallel throughout the day. One of these is the food clock, which is not tied to one specific spot in the brain but rather multiple sites throughout the body.

The food clock is there to help our bodies make the most of our nutritional intake. It controls genes that help in everything from the absorption of nutrients in our digestive tract to their dispersal through the bloodstream, and it is designed to anticipate our eating patterns. Even before we eat a meal, our bodies begin to turn on some of these genes and turn off others, preparing for the burst of sustenance -- which is why we feel the pangs of hunger just as the lunch hour arrives.

Scientist have known that the food clock can be reset over time if an organism changes its eating patterns, eating to excess or at odd times, since the timing of the food clock is pegged to feeding during the prime foraging and hunting hours in the day. But until now, very little was known about how the food clock works on a genetic level.

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Study: Sleep Duration Affects Hunger in Men and Women Differently

A study shows that the more sleep a person gets could reduce their food intake. However, there is a difference in the affect between men and women.

A new study suggests that increasing the amount of sleep that adults get could lead to reduced food intake, but the hormonal process differs between men and women.

"Restricting sleep in healthy, normal weight participants has limited effects on metabolic risk factors and may affect food intake regulating hormones differently in men and women," said Marie-Pierre St-Onge, PhD, FAHA, the study's principal investigator. "We were surprised by the lack of a significant effect of sleep on glucose and insulin, leptin, and sex differences in the hunger-stimulating hormone ghrelin and the satiety hormone GLP-1."

The study, appearing in the November issue of the journal Sleep, tracked the sleep duration, glucose dysregulation, and hormonal regulation of appetite in 27 normal weight, 30- to 45-year-old men and women. Participants provided fasting blood draws, and they were studied under two sleep conditions: Short (4 hours) or habitual (9 hours). Short sleep increased total ghrelin levels in men but not women and reduced GLP-1 levels in women but not in men, a sex difference that has not been reported before. The results suggest that the common susceptibility to overeat during short sleep is related to increased appetite in men and reduced feelings of fullness in women.

"Our results point to the complexity of the relationship between sleep duration and energy balance regulation," St-Onge said. "The state of energy balance, whether someone is in a period of weight loss or weight gain, may be critical in the metabolic and hormonal responses to sleep restriction."

According to the authors, this is the largest controlled clinical investigation of the effects of sleep reduction on hormonal regulation of food intake. The results support a causal role of sleep duration on energy intake and weight control.

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