O problema não é exercício a menos, são calorias a mais (e os fabricantes não ajudam porque confiam que as contamos):
http://theconversation.com/is-it-our-fault-if-we-eat-too-many-calories-63730
Citando:
"The mystery of two conflicting stats was recently solved. On the one hand, official statistics show a decline in calorie consumption across the UK over the last 40 years and, on the other, the population has gained weight over the same period; obesity is on the rise.
The answer comes from the Behavioural Insights Team, a former government policy unit, which reported an increase in the number of people under-reporting the number of calories they consume. People are buying more food and eating as much as 1,000 calories a day more per person than surveys would suggest. And the way that food is marketed offers a number of insights for why this is the case.
The false message from the statistics is not altogether surprising. The main reasons listed in the report are that calorie intake is under-reported, particularly by obese people, increased snacking (which is often not taken into account when people report their calorie intake), and a problem with people eating more than the recommended portion size."
Referido também o halo effect: Se eu comer uma folha de alface, posso comer um prato de batatas fritas.
Os fabricantes / restaurantes também têm de ajudar: Se uma pizza tem 1000 calorias, quem é que come apenas uma quarto de pizza?
Relatório (PDF):
http://38r8om2xjhhl25mw24492dir.wpengine.netdna-cdn.com/wp-content/uploads/2016/08/16-07-12-Counting-Calories-Final.pdf
