Friday, 3 June 2016

obesity, calories, starch and saturated fat

The National Obesity Forum have criticized Public Health England and their Eatwell Guide. There are two polarized opinions expressed here. One side says that obesity is about calories in (from food) and calories out (through exercise). The other side say that calories have nothing to do with obesity.

One side says all starchy foods are good. The other side says all starchy foods are bad.

One side says all saturated fats are bad. The other side says all saturated fats are good.

I think both sides should be ashamed of themselves. The public are confused. Both side are treating all starchy foods as if they are the same. They aren't. Pasta has a low glycemic index, and potatoes have a high glycemic index. That means that pasta eaten in moderation is unlikely to contribute towards the development of diabetes. The starch in potatoes is digested quickly into glucose and pushes up blood glucose and insulin levels soon after eating.

We now know that the fat in cheese, despite being saturated fat, is unlikely to contribute towards heart disease. That's good for me because I like cheese. If I liked burgers though, the news is not so good. We are unsure if beef fat will contribute towards heart disease. All fat can contribute towards obesity though because it is calorie-dense. Now I realize that not all calories are the same. 100 calories-worth of sugar will be treated differently by the body that 100 calories-worth of olive oil. To say though that obesity has nothing to do with calories can't be right.

Why do both The National Obesity Forum and Public Health England have so little to say about the glycemic index? Perhaps they think ordinary people can't take it in. Maybe it seems counter-intuitive (why would starch from pasta and potatoes be so different?). If you like to think of food as something natural and not worry about the science too much then don't like to talk about indexes.

It's not rocket science. They should both get their act together.