Tag Archives: overweight

Sleep deprivation may cause weight gain

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New York: Women who sleep less than five hours put on more weight than those who sleep for longer, says a new study comparing sleeping patterns with obesity.

The study. which took place over a 16-year period, was presented at the recent American Thoracic Society International Conference. It found that women who slept for five hours per night were 32% more likely to experience major weight gain, such as an increase of 33 pounds or more, and 15% more likely to become obese, compared with women who slept seven hours. Women who slept for six hours were 12% more likely to have major weight gain and 6% more likely to become obese compared with women who slept seven hours a night.

The study included 68,183 middle-aged women who were enrolled in the Nurses Health Study. They were asked in 1986 about their typical night’s sleep, and were then asked to report their weight every two years for 16 years.

On average, women who slept five hours or less per night weighed 5.4 pounds more at the beginning of the study than those sleeping seven hours and gained an additional 1.6 pounds more over the next 10 years.

“That may not sound like much, but it is an average amount–some women gained much more than that, and even a small difference in weight can increase a person’s risk of health problems such as diabetes and hypertension,” said lead researcher Sanjay Patel, MD, Assistant Professor of Medicine at Case Western Reserve University in Cleveland, OH.

Dr. Patel noted that this is by far the largest study to track the effect of sleep habits on weight gain over time. “There have been a number of studies that have shown that at one point in time, people who sleep less weigh more, but this is one of the first studies to show reduced sleep increases the risk of gaining weight over time.”

The researchers looked at the women’s diets and exercise habits to see if they could account for part of the findings. “Prior studies have shown that after just a few days of sleep restriction, the hormones that control appetite cause people to become hungrier, so we thought that women who slept less might eat more. But in fact they ate less,” Dr. Patel said. “That suggests that appetite and diet are not accounting for the weight gain in women who sleep less.”

The researchers also asked women about how much they participated in exercise activities such as running, jogging or playing tennis. But they didn’t find any differences in physical activity that could explain why women who slept less weighed more.

“We don’t have an answer from this study about why reduced sleep causes weight gain, but there are some possibilities that deserve further study,” Dr. Patel said. “Sleeping less may affect changes in a person’s basal metabolic rate (the number of calories you burn when you rest). Another contributor to weight regulation that has recently been discovered is called non-exercise associated thermogenesis, or NEAT, which refers to involuntary activity, such as fidgeting or standing instead of sitting. It may be that if you sleep less, you move around less, too, and therefore burn up fewer calories.”

US obesity far worse than estimates reveal

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Harvard: Obesity levels in the US may be 50% higher than previous official estimates. And the fatest people are those in the southern states of the US.

The Harvard School of Public Health (HSPH) has analysed data from a range of surveys to conclude that estimates of obesity in individual states have been too low, by more than 50%, according to a report in the journal of the Royal Society of Medicine.

Obesity is one of the leading causes of morbidity and mortality, causing some 2.6 million deaths worldwide each year. The US survey data on obesity on a national and state level is obtained using information gathered by the Behavioral Risk Factor Surveillance System (BRFSS), which uses telephone interviews and national data is also collected using the National Health and Nutrition Examination Survey (NHANES), which does in-person interviews and follow-up height and weight measurements on people who agree to a clinical exam.

The research, which presents the first-ever corrected estimates of obesity for individual states, found that Southern states have the highest levels of obesity in the country. Using the report’s corrected data for 2000, the highest obesity levels for men were found in Texas (31%) and Mississippi (30%). For women, Texas (37%), Louisiana (37%), Mississippi (37%), District of Columbia (37%), Alabama (37%) and South Carolina (36%) led the pack. States with the lowest prevalence of corrected obesity for men in 2000 were Colorado (18%), District of Columbia (21%) and Montana (21%); for women Colorado (24%), Montana (25%) and Massachusetts (27%).

Lead author Majid Ezzati, Associate Professor of International Health at HSPH, and his colleagues analyzed and compared the data from the two surveys in order to quantify the level of bias when people self-report their height and weight, especially in a telephone interview.

Based on this new understanding of the survey data, the authors found that, on average, women tend to underestimate their weight while men do not. When it comes to height, young and middle-aged men tend to overestimate their height more than women in the same age group. In 2002, the corrected prevalence of obesity in the U.S. population was 28.7% for adult men and 34.5% for adult women, more than 50% higher than previously estimated.

New research casts doubt on BMI weight system

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Washington: A study of 33,000 adults has discovered that putting on a few pounds could actually lengthen your life. According to research published in the American Journal of Public Health most adults may be healthy with an extra half stone than that recommended under the current Body Mass Index(BMI) measuring system.

BMI is calculated by dividing a patient’s weight in kilograms by their height in metres squared. A rating below 18 is regarded as underweight, while above 25 is overweight and a mass index over 30 is regarded as obese.

But while many doctors use the index as a general guideline to good health, the US researchers have found that the average person classified as overweight in the UK actually lives longer.

Changing the current recommended BMI to 26 for men would allow the average male to carry 24lb more than is currently recommended. Women could quite happily tip the scales at half a stone more than suggested.

The study also found that adults with BMIs as high as 35 have the same life expectancy as skinny people who have BMIs of 20.

According to the research, only those with BMIs over 35, equivalent to 17st 6lb for a 5ft 10in man and 15st for a 5ft 5in women, face a marked reduction in life expectancy.

Researcher Dr Jerome Gronniger, of the US Congressional Budget Office, said: ‘This work does not support the idea that reducing weight alone would result in any large mortality risk reduction for most of the population.’

Being overweight can be good for your health, says new CDC study

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Being a little overweight is good for you, a study suggests, but being very thin increases the risk of death, according to the research.

The findings are the result of an analysis by the US watchdog, the Centre for Disease Control. Considered the most comprehensive ever undertaken, it agrees with several smaller studies in recent months.

All show that those who are a little overweight have a lower risk of death than those of normal weight.

As a result, U.S. government experts have dramatically cut the annual number of deaths they blame on people being overweight – from 365,000 to just 25,814.

It means that, officially, more people – 34,000 – now die each year in the U.S. because they are underweight rather than overweight.

Most of these are aged 70 or older. The experts say the definition of a desirable weight range is probably now too low.

They emphasise, however, that there is a difference between being overweight, and being obese – obesity is still a major killer.

Researcher Dr David Williamson, who is overweight himself, said: ‘If I had a family history – a father who had a heart attack at 52, or a brother with diabetes – I would actively lose weight. As it is, I’m comfortable with my size.’ The experts have changed their views on fat and thin people because the new study used more recent data and better statistical techniques, including factors such as smoking, age, race and alcohol consumption.

Based on the new calculations, excess weight drops from the second leading cause of preventable death – after smoking – to seventh.

Biostatistician Mary Grace Kovar said the classification for normal weight is now probably set too low. In addition, ‘overweight’ people are eating more healthily, exercising more, and controlling their blood pressure and cholesterol better than they used to.

The current method of defining obesity calculates BMI, or body-mass index, a person’s weight-to-height ratio. It has been criticised for labelling superfit athletes obese because muscle weighs more than fat.