A Harvard study has made some predictions concerning obesity figures and suggests that they will reach 42% of the population before they become stable in the US.
This idea contrasts with the predictions made by the Centre for Disease Control and prevention when they reported that obesity would stabilise at 32%, the figure it had remained at for the past 5 years. The Harvard study estimates that the stabilization of obesity will occur in another 40 years.
Despite the decrease in the rates of people becoming obese, it is predicted that it will still increase over time. This pertains to the idea that the risk of becoming obese increases if one is in contact with obese people. This was another facet of the study based on a model concerning the spread of the condition throughout social networks like the spreading of the flu virus for example. The information collected reveals that the dynamics for this type of spread is the same as that of the flu even though the mechanisms differ.
The 3 main factors affecting the rate of obesity include personal contact within social networks, lifestyle choices regarding diet and exercise and the rate at which the obese lose weight.
Data from the Framingham heart study which included 75,000 participants show that the average person has a 2% chance of becoming obese any year of their lives due to factors relating to a lack of exercise or poor choice of diet. The possibility increases by 0.5% per obese family member/ friend/ colleague that one is in contact with.
None of this should be interpreted to suggest that obesity is a contagious disease; the study is merely stating that there is a relationship between your body shape and the company that you keep. Put simply, if you hang around with fat people who take no exercise and gorge themselves on Big Macs with incessant regularity then you are likely to have a similar lifestyle and a similar body shape.