Dr Christopher Birt on a recent Lancet study on dairy food, and Sofia Parente of Sustain on the sugary drinks levy and Healthy Start food vouchers
I was recently studying the Lancet paper referred to in your report (Dairy food may protect the heart, study finds, 12 September). As you state, the paper appears to conflict with previous research, and to national dietary advice springing from this, about dietary fats. However, there is an explanation: most previous research had taken place in rich countries in Europe and North America, where dietary fats have contributed 30-45% of total calories consumed, while this new research has taken place mainly in poor or middle-income countries, where fat consumption may be as low as 7% of calories, with calorie content made up by much greater consumption of carbohydrates.
This new research shows that very high consumption of carbohydrates, or very low levels of fat consumption, are associated with increased risk of some cardiovascular diseases; however, saturated fat consumption was not so associated. But we should not really be puzzled by this: most dietary advice in Europe aims to reduce saturated fat consumption to 10% of calories; if total fat consumption in poor countries is lower than 10% of calories, why should we worry about saturated fats?