If you look for the old diabetes diets pre 1945 you will see there is less focus on grains, the problem with modern society is the food companies have all the control and power. Wheat subsidies were given in the seventies and eighties in th uk as an incentive to farmers as the world hunger was going to be solved with this help, thirty years later and food companies get cheap corn and wheat (due to subsidies uk and USA wise) and produce lots and lots of high profit "food" , then governments started promoting grains in the food pyramid, which is now healthy food plate, "grains are a good source of carbohydrate" so is an apple a pear a potato, we never used to eat as many grains, society was slimmer then too.
I have no proof just a long memory and eyes that have seen how we have had food recommendations that have clearly contributed to obesity in the western world.
The low fat diet was promoted as the best diet, all fat was bad, big business lowered the fat and added sugar, boom more profit and bigger waistlines.
Now sugar is the devil and fat is OK even good, but because sugar is being touted as bad fruit is being avoided, boycotted even, I would rather eat diet rich in fruit rather than rich in grains, it's time big business stopped telling us what is healthy, as the only thing healthy about what they tell us is the profit margins.
Sorry to go on but this is really a problem and the nhs is not listening, they just spout the same nonsense that is being proven scientifically to be wrong. If you look at articles in the British medical journals you will see that it is widely known fat does not cause heart disease, you will see the battle going on with big food companies not wanting the researchers published research being made widely available to the general public.
We need to go back to the old family values, cut down the grains, stop snacking between meals and take back control, maybe when we take responsibility for what we eat and chew food properly, stop rushing around eating on the go, walk more instead of driving not only will we feel better and slim down, we will do our bit to reduce our own individual carbon footprint and help in a small way with the climate.