Consciousness of self weight is important for weight loss

Do we have a real perpception of our weight? Do we know if we are really overweight or not? This is what researchers at the University of Illinois investigated when they surveyed over 3,500 college applicants, as part of the Up Amigos project, a collaboration with the Mexican Universidad Autónoma de San Luis Potosi. More than a third couldn't report their weight accurately, and overweight and obese men were more likely to underestimate their weight than women. 

In contrast to what one would thought, almost half of the male volunteers underestimated their weight. Females were more realistic, as 21.2% believed that they were overweight when 27.8% of women were actually overweight or obese. This is even more worrying in the adolescence. According to figures released by the Centers for Disease Control and the International Journal of Pediatric Obesity, American teens are even less likely to report their weights correctly.

Very few participants in the Mexican study overestimated their weight, but those who did were most often female, younger, had parents with less education, and watched more television. Ideal body image changes with exposure to Western media, the researchers noted. The curvier female figure once appreciated in Latino culture is being replaced by the ultra-thin ideal promoted by Western advertisers.

Are diet and exercise enough to lose weight and keep it low?

A new study, published in The New England Journal of Medicine, shows that regaining weight after a period of diet and exercise may be inevitable due to hormones.

Australian researchers found that after losing weight, hormone levels - particularly those that influence hunger - shifted in the body, leading to increase appetites and weight regain.

The study involved 50 adults with a body mass index (BMI) between 27 and 40, who were on a diet and exercise for 10 weeks. After an initial loss scientists found that the levels of appetite-regulating hormones changed, resulting in a regain of 1/3 of the lost weight over the course of a year.

The results of the Australian study corroborate findings in another paper released earlier this year, in which researchers from Spain confirmed that people with high levels of the hormone leptin and low levels of ghrelin are more likely to gain the weight they lost.

Instead of playing the diet and exercise message on repeat - an ineffective longterm weight loss strategy for some - the Spanish authors suggested that endocrinologists and nutritionists consider the possibility of hormonal imbalances when developing weight loss strategies.

Source: http://www.nydailynews.com/life-style/health/diet-exercise-fight-obesity-study-article-1.971052#ixzz1cjDgPJ3S

Caution bariatric surgery for adolescents

Weight-loss surgery for morbidly obese adolescents has become more popular even though many questions about safety and effectiveness remain, according to a commentary published in the New England Journal of Medicine.

Bariatric, surgery produces many benefits for most adult patients: they lose weight and can even have a complete reversal of diabetes. But less is known about the effects of the surgery on a young person who is just finished growing.

Several large and important studies are now underway to examine the risks and benefits of bariatric surgery on teens. Already, at least 1,000 teens a year are undergoing bariatric surgery in the USA despite the lack of long-term data on how the surgery affects them long-term. Until the data comes in from ongoing studies, doctors should tread cautiously in qualifying teens for surgery.

Source: http://www.latimes.com/health/boostershots/la-heb-bariatric-surgery-teens-20111012,0,4705997.story

Sleep deprivation may cause weight gain

A new European study published in the American Journal of Clinical Nutrition augments existing evidence that sleep deprivation can lead to weight gain, not only by increasing appetite, but also by slowing metabolism.

The research conducted in Uppsala University in Sweden found that as little as a single night's sleep deprivation can significantly lower energy expenditure in healthy men. This indicates that sleep plays a prominent role in determining daytime energy production. Previous research has revealed an association between sleep loss and weight gain and also has found that sleep disorders affect blood levels of stress and hunger hormones. In a quest to determine the exact means by which a lack of sleep affects weight, the team of investigators induced differing degrees of sleep conditions in 14 male college students. They divided the men into three groups, consisting of no sleep, normal sleep and limited sleep. The men were then assessed in regard to alterations in factors such as metabolic rate and amount of food consumed.

The energy outlay for activities such as breathing and digestion was lessened by 5 to 20 percent. Higher levels of appetite-regulating hormones and stress hormones were also noted. Even though the appetite hormones were affected, the men did not eat more during the day.

Although research data is inadequate to prove the link between sleep loss and weight gain, evidence is quite sufficient to suggest it. Data collected over the past 50 years reveals an inverse relationship between obesity rates and average sleep time, with the highest obesity percentages found in adults getting the least amount of sleep.

Source: http://www.reuters.com/article/2011/05/16/uk-health-sleep-idUSLNE74F02320110516

How to Fix the Obesity Crisis

Why are extra pounds so difficult to shed and keep off? It doesn’t seem as though it should be so hard. The basic formula for weight loss is simple and widely known: consume fewer calories than you expend. And yet if it really were easy, obesity would not be the nation’s number-one lifestyle-related health concern. For a species that evolved to consume energy-dense foods in an environment where famine was a constant threat, losing weight and staying trimmer in a modern world of plenty fueled by marketing messages and cheap empty calories is, in fact, terrifically difficult. Almost everybody who tries to diet seems to fail in the long run—a review in 2007 by the American Psychological Association of 31 diet studies found that as many as two thirds of dieters end up two years later weighing more than they did before their diet.

From:Scientific American Magazine, February 2011