Tag Archives: Weight Loss

Sleep Restriction Results In Weight Gain Despite Decreases In Appetite And Consumption

According to a research abstract presented on June 8 at SLEEP 2009, the 23rd Annual Meeting of the Associated Professional Sleep Societies, in the presence of free access to food, sleep restricted subjects reported decrease in appetite, food cravings and food consumption; however, they gained weight over the course of the study. Thus, the finding suggests that energy intake exceeded energy expenditure during the sleep restriction

Results indicate that people whose sleep was restricted experienced an average weight gain of 1.31 kilograms over the 11 days of the study. Of the subjects with restricted sleep who reported a change in their appetite and food consumption, more than 70 percent said that it decreased by day 5 of the study. A group of well rested control subjects did not experience the weight gain.

According to lead investigator Siobhan Banks, PhD, a research fellow at the University of South Australia and former assistant research professor at the University of Pennsylvania School of Medicine, it was surprising that participants did not crave foods rich in carbohydrates after sleep restriction, as previous research suggested they might. Results indicate that even though physiologically the desire to eat was not increased by sleep loss in participants, other factors such as the sedentary environment of the laboratory and the ability to snack for longer due to reduction in time spent asleep might have influenced the weight gain.

“During real-world periods of sleep restriction (say during shift work), people should plan their calorie intake over the time they will be awake, eating small, healthy meals,” said Banks. “Additionally, healthy low fat/sugar snacks should be available so the temptation to eat comfort foods is reduced. Finally, keeping up regular exercise is just as important as what food you eat, so even though people may feel tried, exercising will help regulate energy intake balance.”

The study involved 92 healthy individuals (52 male) between the ages of 22 and 45 years who participated in laboratory controlled sleep restriction. Subjects underwent two nights of baseline sleep (10 hours in bed per night), five nights of sleep restriction and varying recovery for four nights. Nine well rested participants served as controls. Food consumption was ad libitum (subjects had three regular meals per day and access to healthy snacks, and during nights of sleep restriction subjects were given a small sandwich at one a.m.).

Abstract Title: Sustained Sleep Restriction in Healthy Adults with Ad libitum Access to Food Results in Weight Gain without Increased Appetite or Food Cravings
Presentation Date: Monday, June 8
Category: Sleep Deprivation
Abstract ID: 0385

Source:
Kelly Wagner
American Academy of Sleep Medicine

Regulating the sugar factory in diabetes

Scientists in Sydney and Boston believe they may have identified a gene that controls abnormal production of sugar in the liver, a very troublesome problem for people with diabetes.

The liver is the sugar factory for the body – when blood sugar (glucose) levels fall, the liver makes and releases more. In people with diabetes, especially Type 2 diabetes, the liver doesn’t stop making sugar when it should, so blood sugar levels can rise overnight while they sleep even though they haven’t eaten.

Dr Jenny Gunton, diabetes specialist and endocrinologist from Sydney’s Garvan Institute of Medical Research, in collaboration with Dr Xiao Hui Wang and Professor Ronald Kahn from Harvard Medical School and Joslin Diabetes Centre in Boston, have published their findings in the journal Cell Metabolism, now online.

“A lot of my patients will complain that they go to bed with a blood sugar of 5 and wake up with a blood sugar of 12,” said Dr Gunton.

“It upsets people when their blood sugar behaves as if they’re getting up in the night and having a really big snack. I have to tell them it’s just one of those unfair things about having diabetes.”

People with Type 2 diabetes do not produce enough insulin in the pancreas after a meal. At the same time, they are less able to use that insulin to move glucose into fat and muscle cells, a condition known as ‘insulin resistance’.


With her colleagues in Boston, Gunton has been studying a transcription factor, or kind of ‘master regulator’, called ARNT, which controls expression of other genes involved in processes like glucose breakdown and insulin production. In an earlier study, the group showed that there is 90% less ARNT in insulin-producing cells of people with Type 2 diabetes.

The current study looks at how ARNT might be affecting the liver, and its results confirmed Dr Gunton’s suspicions. “We’ve shown that there’s likely to be decreased ARNT in the liver of people with Type 2 diabetes compared to people without Type 2 diabetes,” she said.

“Working with mice, we found that glucose levels were elevated and there was glucose production from a ‘precursor’, a source not normally metabolised.”

Other results in the study show that to some extent ARNT is regulated by insulin, so that insulin resistance in itself will contribute to a decrease in ARNT. If liver cells are treated with insulin, there will be a small increase in ARNT protein. The insulin will also help move the ARNT into the nucleus of the cell, where it does its job as a master regulator.

The paper concludes that a decline in ARNT isn’t limited to the beta cells of people with Type 2 diabetes. ARNT is also reduced in other important diabetes-related tissues like the liver.

Dr Gunton believes that if a new drug could be developed to increase ARNT activity in the liver, then it may be possible to shut down abnormal sugar production and improve blood sugar control in people with diabetes.

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ABOUT GARVAN

The Garvan Institute of Medical Research was founded in 1963. Initially a research department of St Vincent’s Hospital in Sydney, it is now one of Australia’s largest medical research institutions with nearly 500 scientists, students and support staff. Garvan’s main research programs are: Cancer, Diabetes & Obesity, Immunology and Inflammation, Osteoporosis and Bone Biology, and Neuroscience. The Garvan’s mission is to make significant contributions to medical science that will change the directions of science and medicine and have major impacts on human health. The outcome of Garvan’s discoveries is the development of better methods of diagnosis, treatment, and ultimately, prevention of disease.

All media enquiries should be directed to:
Alison Heather
Science Communications Manager
+61 2 9980 1224
+61 434 071 326
a.heather@garvan.org.au

More than a bad night’s sleep

Study finds sleep apnea widely undiagnosed among obese type 2 diabetics

Sleep apnea has long been known to be associated with obesity. But a new study published in the June issue of Diabetes Care finds that the disorder is widely undiagnosed among obese individuals with type 2 diabetes – nearly 87 percent of participants reported symptoms, but were never diagnosed.

For those with untreated sleep apnea, it doesn’t just mean their sleep is disrupted; existing research shows that it can also mean an increased risk of heart disease and stroke.

“The high prevalence of undiagnosed, and therefore, untreated sleep apnea among obese patients with diabetes constitutes a serious public health problem,” said Gary Foster, PhD, lead author and director of the Center for Obesity Research and Education at Temple University.

The new study, called Sleep AHEAD, looked at 306 obese patients with type 2 diabetes already enrolled in the Look AHEAD trial, a 16-site study investigating the long-term health impact of an intensive lifestyle intervention in 5, 145 overweight or obese adults with type 2 diabetes.

Each participant had a sleep study (polysomnogram) that measures various breathing and brain activity during sleep. Participants also filled out a series of questions about symptoms related to sleep (snoring, sleepiness during the day), and had their weight, height, waist and neck circumferences measured.


Researchers found that 86.6 percent of participants had sleep apnea, yet reported never being diagnosed. More than 30 percent of these had between 16 and 20 episodes per hour where they would stop breathing, and 22 percent had more than 30 episodes per hour, considered severe sleep apnea. Most of these also had a larger waist circumference, which researchers found, along with higher BMI, to be significantly associated with sleep apnea.

Obesity has long been known to be associated with sleep apnea, but researchers say that these findings are alarming.

“Doctors who have obese patients with type 2 diabetes need to be aware of the possibility of sleep apnea, even if no symptoms are present, especially in cases where the patient has a high BMI or waist circumference,” said Foster.

Currently, more than half of obese or overweight individuals have diabetes, the seventh leading cause of death in the United States.

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Other authors on the study were Kelley Borradaile, PhD from Temple University; Mark Sanders, MD, Anne Newman, MD, David Kelley, MD, from the University of Pittsburgh; Richard Millman, MD, Rena Wing, PhD from Brown University; Garry Zammit, MD from Clinilabs; Thomas Wadden, PhD, Valerie Darcey, MS, and Samuel Kuna from the University of Pennsylvania; F. Xavier Pi SUnyer from Columbia University; and the Sleep AHEAD Research Group. Funding was provided by grants from the National Institutes of Health: National Heart, Lung, and Blood Institute and National Institute of Diabetes and Digestive and Kidney Diseases.

Action of ghrelin hormone increases appetite and favors accumulation of abdominal fat

The ghrelin hormone not only stimulates the brain giving rise to an increase in appetite, but also favours the accumulation of lipids in visceral fatty tissue, located in the abdominal zone and considered to be the most harmful. This is the conclusion of research undertaken at Metabolic Research Laboratory of the University Hospital of Navarra, published recently in the International Journal of Obesity.

Ghrelin is a hormone produced in the stomach and the function of which is to tell the brain that the body has to be fed. Thus, the level of this secretion increases before eating and decreases after. It is known to be important in the development of obesity, given that, on stimulating the appetite, it favours an increase in body weight, explained Ms Amaia Rodríguez Murueta-Goyena, doctor in biology and main researcher of the study.

However, researchers at the University Hospital of Navarra have discovered that, besides stimulating the hypothalamus to generate appetite, ghrelin also acts on the tabula rasa cortex. They observed how this hormone favoured the accumulation of lipids in visceral fatty tissue. In concrete, it causes the over-expression of the fatty genes that take part in the retention of lipids, explained Ms Rodríguez.

It is precisely this accumulated fat in the region of the abdomen that is deemed to be most harmful, as it is accompanied by comorbilities, visceral obesity being related to higher blood pressure or type 2 diabetes. Moreover, being located in the abdominal zone and in direct contact with the liver, this type of fatty tissue favours the formation of liver fat and increases the risk of developing resistance to insulin. Normally, on being associated with hypertension, high levels of triglycerides, resistance to insulin and hypercholesterolemia, visceral fat favours the metabolic syndrome, the researcher pointed out.

Ghrelin can show itself in acylated or deacylated form, the difference being in the octanoic acid present in the composition of the former, according to Ms Rodriguez. Previously it was thought that only the acylated form was active in the process of weight increase, but many studies point to both hormones being biologically functional.


Future development of pharmaceutical drugs

This discovery of the twin action of ghrelin on the organism opens the door to future treatment for obesity and which, for the time being, is limited to in vitro studies in cell and animal models, the University Hospital researcher pointed out. This inclusive perspective of the functioning of a hormone is necessary in order to design effective pharmaceutical drugs. There are many hormones that intervene in the control of appetite in the hypothalamus and, at the same time, can act on other organs, such as the liver, the muscles or fat, for example. Thus, the medication developed should block the action of ghrelin both on the hypothalamus and on the accumulation of abdominal fat.

At the same time, stated Ms Rodríguez, it has to be taken into account that this hormone also acts on the liver and favours the capturing of glucose in the muscle. They observed that the concentration of acylated-form ghreline in the blood increases amongst obese persons and particularly when these, moreover, suffer from diabetes. Thus, obese persons with diabetes have greater tendency to accumulate visceral fat than normoglycemic obese persons. This is a little-studied field which has to be investigated in order to develop pharmaceutical drugs which annul this action of ghrelin.

Blood analysis and stimulation of adipocytes

The research undertaken at the Metabolic Research Laboratory of the University Hospital of Navarra principally involved the analysis of the blood of 80 patients, both obese and thin, and in the stimulation with ghrelin of the fatty cells from surgical operations. First they analysed the ghrelin levels in the blood. Then, based on the biopsies of visceral fat obtained from 24 patients subjected to various operations, the adipocytes or fatty cells were separated and subsequently stimulated with hormone, which enabled the researchers to evaluate the changes generated in the genes that favoured the lipid accumulation in these isolated adipocytes, explained the researcher.

Facing the Weight Loss Problem

by Jeffrey Sloe

Are you struggling with your weight? I believe, as the new year approaches and you start to think about making resolutions for the up coming year, it’s time to take serious action. We are all getting older, and the times are getting worse. Not only are we facing the worst economic times in the history of the US, but we are also facing an increase in obesity which is bordering on an epidemic. Continue reading

Are Artificial Sweeteners Keeping You Fat?

by Jason Yun

You just very might well be sabotaging yourself when it comes to losing weight and body fat, and you don’t even know it. You think you are doing everything right, exercising regularly and watching what you eat. That can be extremely frustrating. To the point where most people would give up. Continue reading

The Dangers Of Belly Fat

by Derek Cladek

Belly Fat Problems

It is easy to look in the mirror and see fat around your midsection and you have probably always wanted to get rid of it. Your main reason to get rid of that midsection belly fat is probably because you want to look good in a bathing suit or impress someone special. Well, maybe I can give you a little more motivation to get rid of that belly fat other than just to look good. Recent studies have shown that people who struggle with fat in the midsection are more at risk at acquiring type 2 diabetes, cardio vascular disease and metabolic syndrome, and that is because fat around the midsection can be caused my a damaged metabolism. It’s sounds scary, and probably because it is scary. Continue reading

Food Addiction: Getting Off Sugar

by Carol Solomon

If you are worried about food addiction, then you are probably concerned about your sugar intake. I do NOT mean that you should never have your favorite treats again. But sugar is definitely an addictive substance. The more you eat, the more you want. The less you eat, the less you want. To me, I don’t want ANY substance running me! Period. Continue reading