Overweight and obesity has increased significantly recent decades among children and teenagers. Studies have shown that in some Western countries, up to one third of children and teenagers are obese. The New England Journal of Medicine recently published a study where the relationship between BMI (body mass index) and heart disease in 2.3 million youths from Israel were examined. The special features of this study are the large sample of youths who were investigated, and the correlation between BMI in teenagers and heart disease in midlife.
Every once in a while we here about this magic medicine. What about a drug to make your muscles stronger, your heart healthier, power-up metabolism, reduce body weight, improve blood flow in your brain and many other benefits? Wouldn’t that be great?
Although many people would say yes, we commonly meet many that are against that idea for a number of reasons. For example, it’s well known that physical activity levels have decreased dramatically in the past 100 years in almost all countries, so it’s been thought that a drug to ”copy” exercise would be just one more reason NOT to go out for a workout. And how about elite sports? Doping is an increasing problem in the field, so another pill to enhance performance could lead to more abuse of such substances. Or perhaps more important: if exercising promotes so many benefits for health, would the world really need an expensive drug that does (part of) the same thing?
The prevalence of obesity is increasing worldwide, and the different approaches to solve the problem are as creative as they are numerous – from miracle pills to celebrity diets only consisting of lemons, cayenne pepper and maple syrup. From a more evidence-based point of view, the main perception is that there are no quick fixes – loosing weight requires hard work and motivation to change habits, a change that should be maintained throughout life. However, even within the medical field there is not full agreement of what is the most effective way to lose weight. A recently published Norwegian study compared two common treatments of obesity, to investigate which of them having best results.
Patients were randomly selected to one of two groups: 10 weeks with diet counseling and 3 hours exercise/week, or 12 weeks with 3 course days per week with exercise and diet counseling. The last group was even followed once a month throughout the year, after the intervention period.
Not surprisingly, the intensive program had the best results, with an average weight loss of 13 kgs, as well as a significant increase in quality of life. On the other hand, the participants in the moderate group had very limited effect. According to forskning.no, the researchers believe that a key factor to succeed is that the intervention program was home-based – obese patients often have a very good effect of longer stays at obesity treatments centers, but when they return home, they are not able to maintain the habits they learned at the course. Through the combination of intensive days of exercise and diet counseling and trying to adapt the habits to every-day-life inbetween, the participants had a great opportunity to continuously get feedback on what was working and what was not when they were home.
Still, lots of questions remains unsolved regarding weight loss research. For instance, it is often claimed that only restrained eating, not exercise, has effect on weight loss. On the other hand, some tells you to eat whatever you want as long as you are burning more calories than you are consuming. The third suggestion is restrained eating in combination with intensive exercise. I’ll challenge some of the CERG researchers to write something about this on the blog, so keep following us!
Maria Henningsen, CERG
Is being overweight healthy and a predictor of longer life? In contrary to well established notion of a healthy weight, recently published studies have shown us another side of this picture and introduced a phenomenon generally known as the “obesity paradox”. In simple words, this paradox means that overweight people are healthier than normal weight people.
Let us first define – what is obesity? Public health professionals and physicians use a term called body mass index (BMI), which is a measure for human body shape based on an individual’s weight and height. It is calculated by weight in kilograms, divided by square of height in meters. A healthy BMI is considered to be above 18.5 and below 25. Overweight people usually have a BMI between 25 and 30. Someone with a BMI of ≥30 is classified as being obese or simply fat. Over the last few decades, obesity has been known as a risk for cardiovascular disease. And there have been lot in public health guidelines to reduce the body weight.
However, there is evidence in scientific literature that being overweight can lead to a longer life. A recent study involving nearly 2.9 million people reported a 6% decreased risk of death for people who were overweight (BMI 25-30) than those considered to have a healthy weight. Moreover, mildly obese people (BMI 30-35) had similar risk of dying as the healthy weight people. The conclusion of this large scale study was that “overweight is associated with significantly lower all-cause mortality”.
But is it the full picture and the benefits of gaining weight in regard to longer survival well-founded? Probably not. The main criticism of all studies which have shown a beneficial effect of increased weight with reduced mortality is that they might not have taken good care of other risk factors when reporting their results. This makes it difficult to prove independent associations between weight gain and mortality. For example, the information about the numbers of years spent free of ill-health in people across different BMI categories would help to better understand the association of overweight and mortality. It might be possible that overweight people get an early medical treatment such as to control blood pressure, cholesterol, and a strict check on diabetes status. This, in turn, helps to keep a favourable cardiovascular profile.
The change in other risk factors such as smoking, healthy eating and physical activity could also affect the body weight association with mortality. The evidence of this came from a study that reported the association of body weight and mortality in people who quit smoking. People who quit smoking had lower risk of heart disease even they had a significant gain in body weight. So, it does not mean that increase in body weight resulted in reducing the risk of heart disease. The health gains from giving up smoking were the main reason for a lower risk of having heart disease.
Another study to explain the obesity paradox reported that people can be obese yet physically healthy and fit and at no greater risk of heart disease or cancer than normal weight people. Being physically active and having a higher fitness were more important than being overweight in this study.
Still, the so-called obesity paradox exists, and we have not yet understood it. However, we should be very careful when interpreting the benefit of being overweight for long survival. So far, the advice to people is to keep a healthy weight by healthy life style factors, such as physical activity, quit smoking and healthy eating.
Javaid Nauman, post doc at CERG.
This Christmas, Norwegians are going to sit 30 minutes longer by the food table than the rest of the year, according to Statistics Norway. This is of course a nice way to spend time with friends and family – but remember that what you put on the table may have long-term consequences for your health. Maybe this funny reminder from the blog www.nomoreaddedsugar.com can help you limit your fat and sugar intake during the holiday? You can also get tips for a healthier Christmas at DN Aktiv (in Norwegian).