Australasian Science: Australia's authority on science since 1938

When Can Weight Loss Be Dangerous?

By Tim Olds

Unless they are extremely obese to start with, people who lose weight die younger.

The full text of this article can be purchased from Informit.

If you’re overweight or obese – and that’s about 60% of us – then losing weight will improve your blood pressure, blood fats, blood glucose levels and insulin sensitivity. Weight gain has the opposite effects.

You would think, then, that overweight or obese people who lose weight would live longer, given that cardiovascular disease and diabetes are two of the major killers in Australia. This logic has driven a number of public health campaigns that urge anyone who is overweight or obese to lose weight. You may have seen the Measure Up campaign – the poor bloke huffing and puffing his way along the tape measure getting fatter and fatter, unable to keep up with his young daughter.

While that seems to make sense, it isn’t true. I’ve indicated before in this column that overweight people live longer, but now there is even more perplexing news: unless they are extremely obese to start with, people who lose weight die younger.

First, let’s look at some of the studies. Danish epidemiologist Thorkild Sørensen followed 2957 Finns from 1975 to 1999.1 They were aged 24–60 at the start. In 1975 he asked them whether they intended to lose weight – about one-third said they did. Relative to those who did not intend to lose weight, and whose weight remained stable 6 years later, those intending to lose weight who did actually lose weight had an 87% greater chance...

The full text of this article can be purchased from Informit.