The Robert Wood Johnson Foundation (RWJF) released a report today that suggests children need to reduce their caloric intake or increase their expenditure by an average (and not individual) amount of 64 calories or face a future where they are heavier by 4 pounds than the cohort that went before them.
Meaning that around 16% of adolescents were obese in 2007-08 and if things don't change, the obesity rate will rise to 20% for year 2020.
Things must change - this is not an acceptable outcome.
Children who are obese tend to remain obese and the consequences of obesity across a life span are significant and disabling.
Whether or not '64' is the magic number is questionable. It is derived from population wide averages - meaning it looks at the weights of children in aggregate and finds the average number that all kids would have to lower to prevent the rise in obesity for the group. However, some children are already obese and would have to lose weight before sustaining it (meaning a 100+ calorie deficit), and some children are NOT overweight (meaning a 0 calorie deficit).
Non white girls are heavier than white girls and boys are generally less heavy than girls. Living in a poor neighborhood also increases the risk of obesity - i.e. living in a food desert that lacks access to affordable, lower calorie foods.
That being said - what is 64 calories? It is easier to quantify as intake because expenditure depends on ones body weight, fitness, and intensity of exercise - so we really can't say -for instance, 63 cals= a 30 minute walk. We can say how much 64 calories is in food. For example, it is one and a half teaspoons of oil or pats of butter. It is the extra calories in 2% vs skim milk. Calories could easily be reduced if SSBs were cut out of schools (as RWJF suggests - NO SODA).