Is it smart to lose weight?

This seems a frivolous question with an obvious answer. But not so fast with your response. Let’s first clarify the question. If you find yourself losing weight without any planning by you, then your weight loss could be a sign of a medical condition. Off to your GP please. Then there are those that really don’t need to lose weight; a distorted view of a normal body shape has probably sent them into the world of eating disorders and weight loss. They too need some outside help.

Intentional weight loss
Let’s just say that your mirror has spoken in a frank manner: “Hey chunky! What’s with the extra curve?” You both then agree that a few kilos could be safely left behind and you join the masses that are “watching their weight”.

Every health authority urges you towards a healthy weight. It makes sense. An overweight person will likely experience a drop in blood cholesterol and blood pressure, while their insulin sensitivity improves. Perfect.

But there is another important question. Will this weight loss make you live longer? A Danish research group says: “Maybe, maybe not”.

Weight loss may not be healthy
At the Institute of Preventive Medicine, Copenhagen, five scientists checked out the research on weight loss and mortality and found that, out of nine studies, only two found a decreased mortality with intentional weight loss in healthy folk. Four found no difference in life span and, disturbingly, three studies found an increased risk of early death in healthy adults over a follow-up period of 13-22 years.

We have to be careful how we interpret these results. It may be that those who lost weight quickly are at a greater risk of early death because they tend to lose more muscle than those that lose weight gradually. There was a hint that mortality rate was higher in people under 60 years of age so they may have already had a pre-existing disease that was not obvious at the start of the study.

So, should you lose weight?
That is your choice. In some cases, it may be a necessity with extra body fat causing joint pain or uncontrolled diabetes. If you are less than 5kg (11lb) overweight, intentional weight loss may be more a cosmetic decision, rather than a health decision.

This review study raises many questions. For example,are those that have ‘dieted’ many times at greater risk than those that have intentionally lost weight 1-2 times? There are some pretty unhealthy ways to lose weight (purging, fad diets etc) that may have reduced life span too. Anyway, I think I’ll play it safe and make sure I don’t lose weight this Christmas.

Reference: Nutrition Reviews 2008; 66(7): 375-386

What else can make you fat?

Eat less food; do more exercise. Boring as it sounds, we are told that is the key to weight loss. Who willingly enjoys eating less food? History tells us that humans really don’t like to change their eating habits, or any habit really. Which means they prefer not to increase their energy expenditure either, as that means more walking, going to the gym, and even possibly sweating.

Climate change is good for you
Twenty scientists pooled their expertise and the results from around the world to present an argument that if we focus solely on food and exercise in weight control, we have missed other aspects of life that can make us fat.

Climate change may be bad for the environment, but it is great for the waistline. What is the temperature of your house, your vehicle and your office? Many people live at 25ºC (77ºF) all year round. You only need a jacket to wear to get from one climate-controlled venue to another. At 25ºC you will feel very comfortable. Experiencing cold or hot makes your body work and burn energy (kilojoules/Calories). Shivering and sweating both require “work” from the body. There is suggestive evidence that when you feel hot, you also eat less food.

The study in the International Journal of Obesity reports that the average temperature in an UK home rose from 13ºC/55ºF in 1970 to 18ºC/64ºF in 2000. Some Australians will remember having four-eighty air-conditioning in your car in the 60s and 70s. Now every car has “air”. (Four-eighty air-con? Wind down four windows and drive at 80 km/h for a cooling effect).

Quit campaign fattens you up
It is well known that smokers can gain a few kilos when they quit. Conversely, some young women are known to smoke to dampen their appetite. US scientists have estimated that smoking cessation is responsible for 25% of the increase in chubby men and 17% of the extra plump ladies out there. One wonders if some people have a brutal choice: smoke or be fat.

Sleep it off
In 1908, it is estimated that the average adult got nine hours of snooze each night. Now that figure is believed to be closer to seven hours, meaning that we have gone from 40 winks down to 31.1 winks. The authors refer to studies revealing that the less sleep you get, the larger your girth, and this goes for both kids and adults. Sleep deprivation appears to influence hormonal levels involved in weight control, such as higher levels of the hormone ghrelin, which increases appetite. So, next time your partner calls out “Hey, lazy, gedowdabed”, you could remind them of your weight control program.

Wait, there’s more…
The authors offer many other reasons for increased body mass over the years, including Mum’s age. Women are delaying having children until their late 20s or early 30s. Every 5 years later in Mum’s life means a 14% increased chance of having a child who becomes obese.

Even if any of these factors has only a very small effect then, coupled with those two choccy biscuits for morning tea, they could be making a big difference to whether you accumulate fat cells or reduce their size.

Reference: International Journal of Obesity 2006; 30: 1585-1594