A great place for seeing the obesity trends back to 1990 here in the United States is on the site The State of Obesity. It has current data and has a very useful and intuitive set of charts that has tracks for all the states. The data is presented in such a way that the relationships are instantly obvious.
Tracking obesity is important because it is a precursor to many serious diseases including hypertension, which is a major causal factor in cardiovascular disease and death. Observe that obesity in Oregon in 1990 was 11% and by 2016 had risen to 28.7% and the trend is still dangerously upward.
Hypertension in 1990 for Oregon was 21% and it has risen to 30.1% in 2015 and it was about average for the US. The current population of the US is 325.7 million (2017) and half of these people will have adverse effects from their obesity and resulting hypertension which will lead to their deaths being earlier than if they had known how to control their weight. The extraordinarily sad truth is that the scientists made some very poor suggestions for how the public should go about controlling their weight. For diabetics, they promoted the lowering of blood glucose, and the quick way to do that was to give insulin to people with high levels which did, in fact, lower their blood sugar. The problem was that the insulin did that by forcing the sugar into the cells and not letting it out, and the cells then convert that extra sugar to fat. A procedure that does work is to allow the cells to pump the sugar out into the blood by having the person fast. The best way to do this is with a voluntary intermitent fast.
Instead, what was recommended, and still is by some, is to keep the food intake very low by having the obese person frequently eating small quantities of food. The idea is to stabilize the glucose in the blood at a smooth low level, but that doesn’t work because the body never has a chance to clear out the sugar that is in the cells.
The normal human cycle is to eat during the day and fast overnight which lets the body clear out excess sugar. The way it does that is to dump excess sugar into the blood where it can be taken away. If there is too much insulin there in the bloodstream the sugar is prohibited from leaving the cells.
A normal weight person who doesn’t eat for twelve hours overnight will maintain a reasonable weight. If they become a little overweight, not obese, they may lengthen their fast until noon and then eat normally. If they are about BMI 30, limiting their eating to the hours from noon until 6pm will drop their weight about a pound or two per month. If they are diabetic this method will probably work but it must be done more carefully by monitoring the blood sugar so they don’t get outside of reasonable glucose levels.
Gentle overnight fasting is the way for most normal people to bring their BMI to a healthy condition.