The National Obesity Forum UK has hit the headlines this week with a new report stating that the dietary guidelines over the last 40 years which have recommended low fat diets have caused the current obesity crisis. NOF have recommended a high fat diet to avoid obesity and diabetes. Is it as clearcut as that?
When the first dietary guidelines were issued in the USA and UK about 40 years ago, they did recommend reducing fat intake, in particular saturated fat intake. That recommendation was based on the best available evidence at the time. The guidelines also recommended eating a variety of food, reducing sugar intake, increasing fruit and vegetable intake, and reducing salt intake.
However, the food industry at the time latched on to the low fat message, and in no time, the supermarket aisles were filling up with reduced fat, low fat,and fat free options which were heavily marketed as the healthy option. Far from being healthy options however, these products were generally high in refined (added) sugars and “empty” calories (i.e. not providing micronutrients such as vitamins and minerals). Consumption of these products soared, and around that time obesity figures also began to rise. The resultant population weight gain was not simply due to reducing fat intake, it was what it was being replaced with – very often highly processed high sugar high calorie foods. Other factors were also at play: accessible of convenience foods, gradually increasing portion sizes, increases in sedentary behaviour with technological advances and increases in working hours, increased car ownership, and multiple other factors which came with increased urbanisation and globalisation. All of these factors come together to create what is now termed our “obesogenic environment”, i.e. the modern world that we now live in is in itself promoting obesity.
So have dietary guidelines had a part to play in the obesity crisis? Unfortunately, by and large, dietary guidelines were not and are not followed. Fruit and vegetables intakes are still suboptimal, and there continues to be a heavy reliance on processed or discretionary foods. Healthy eating is not about single nutrients or individual foods. It is about eating a variety of foods from each of the food groups and minimising intake of processed foods.
Reaction to the NOF from various experts can be found here:
The British Dietetic Association response can be read here: