In an effort to contain the ever-expanding levels of obesity in the UK, the Government is considering levying a tax on unhealthy foods such as those rich in fat. Perhaps not surprisingly, the so-called ‘fat tax’ has attracted some criticism from those keen to stay out of the clutches of the nanny state. Also, some quarters in the nutritional establishment have questioned how effective punitive pricing of fattening food would be in changing our eating behaviour, and have suggested subsidising more nutritious fare instead. It is likely that a strategy that makes healthy food more accessible to all is likely to attract widespread support. However, I wouldn’t bank on the Government, and Gordon Brown in particular, being too keen to fork out for such a food subsidy scheme.
Whatever reservations there may be about the use of a fat tax in an assault on obesity, received wisdom is that it will at least tip the scales in our favour. After all, studies show that rates of obesity are higher in countries that consume plentiful amounts of fat (such as USA, the UK and Australia) compared to those where fat intake is lower (such as India and China). However, some scientists have pointed out that the disparity in rates of obesity between different countries may have other explanations. Higher levels of activity and more limited access to food, for instance, may explain why individuals living in poorer countries appear to be relatively immune to the problems of overweight and obesity.
A more accurate picture of the broad relationship between fat in our diets and fat sequestered in our bodies can be gained from studies comparing countries of similar economic development. In one such study published in the European Journal of Clinical Nutrition, the proportion of calories contributed by fat was found to range from 25 – 47 per cent across 18 countries. However, this wide variation in fat intake appeared to have no bearing on body weight in men. Even more surprising was the finding that, in women, higher levels of fat consumption were clearly associated with a reduced risk of excess weight. This evidence should perhaps give the Government pause for thought before it ploughs ahead with its plans to slap a tax on fat.
Interesting though such research is, it is not as good for predicting the likely effects of the fat tax than studies which examine the effects of low-fat eating. Relatively short-term studies of low-fat dieting in a controlled setting (that may have little to do with real life) have generally been found to elicit only modest weight loss. Unfortunately, the effects on weight of longer-term fat restriction are even less impressive: a 2002 review of relevant studies found that the average weight loss in individuals eating a diet lower in fat for 18 months was none at all.
With rates of obesity having trebled in the UK in the last 20 years, it is not surprising that the Government feels compelled to act. However, if the policy-makers in Downing Street are serious about stemming this tide, then it is likely that they will need to invest in a long-term and broad-ranging strategy aimed at supporting individuals in their efforts to eat better and be more active. The evidence suggests that the chances of a tax on fat bringing about a reduction in our collective weight are very slim indeed.
