Standard nutritional advice tends to frown on processed food and to canonise fresh whole food. In a recent article in The Atlantic, however, David Freedman argues cogently that this approach is dooming many people to obesity and disease. We may need to rethink public policy on healthy eating.
If you consistently ingest more calories than you burn off, you will become obese. Obesity is corrosive to health, predisposing one to such problems as heart disease, diabetes and osteoarthritis. The developed world is suffering from an obesity epidemic. Obese young adult and middle-aged Americans die on average 10 years before their non-obese peers.
There is a nutritional consensus that the healthiest eating is based on a diet of vegetables, fruit, wholegrains, fish and low-fat meat such as chicken. What is not emphasised enough is that one should eat in moderation. Obesity results from ingesting too many calories, whatever the provenance.
Processed food has been subjected to a process to extend its shelf life frequently with the addition of chemical preservatives, flavour enhancers and artificial colourants. These foods are often high in fat and salt.
Some are processed to reduce fat and salt, and many have desirable additives such as vitamins and minerals. The supermarket sells a bewildering array of processed foods, many proclaiming that they are “low-fat”. But they do not advertise that they often have more sugar or salt to compensate for the bland taste.
The charge is frequently made that the food industry has addicted the public to processed foods by adding excessive amounts of the three big “baddies” , fat, sugar and salt, which are described as bad for the health but craved by human taste buds. Fat and sugar are calorie-rich. Fat is particularly high having about four times the calories per unit weight as sugar. Salt has no calories but does tend to raise blood pressure and is best ingested in small quantities. The most publicised examples of over-indulgence in processed food are the high-calorie, high-salt meals sold in fast-food outlets. These foods are tasty, convenient and relatively cheap, but very fattening.
But there is no clear evidence that processing food makes it intrinsically unhealthy. Nobody claims that frozen peas or tinned salmon are unhealthy. It is the over-eating of processed food that contributes to obesity. Of course, overeating “quality” food can do so too. A recent survey found that recipes from popular TV chefs have considerably more calories and less fibre per portion than supermarket ready meals.
Pipe dream
In an ideal world everyone would consistently eat fresh whole foods and avoid high- calorie, salty processed food. However, Freedman argues that this is a pipe dream and current policies promoting this ideal abandon the obese and condemn them to their unhealthy eating habits.
He argues that illness levels and indicators increase and levels of educational attainment decrease as you move towards the poorest end of the socio-economic scale. There is a big difference between well-off middle-class communities with low levels of obesity, where people are health-conscious and eager to adopt the latest medical advice, and poor communities with high levels of obesity, where nutritional advice has little impact and where there is no social pressure to encourage healthy lifestyles.
In the latter scenario, health education programmes find it difficult to persuade people to avoid cheap, tasty and convenient takeaways in favour of chopping and boiling vegetables. Witness the glacially slow progress in persuading the 29 per cent of the population who still smoke (paying €9.40 per pack) to quit.
The food-processing industry is worried by the bad press it receives and is willing to modify processed foods in line with nutritional guidelines. Freedman argues that the only effective way to deal with obesity is to persuade the food industry to produce healthy products, retaining flavour and remaining relatively cheap, and to use their marketing abilities to sell these products, thereby improving the diets of people who are growing obese and sick on poor quality processed food.
This advice makes sense, but only if it is backed by legislation specifying nutritional standards that must be met in processed foods. Without legislation, competition between food companies would quickly cause food quality to spiral downwards.
William Reville is an Emeritus Professor of Biochemistry and Public Awareness of Science Officer at UCC,
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