Only you are suggesting that advertising from the food sector alone is responsible for problems of obesity.
Hence you can turn this all in to 'the state wants poor people to be fat'. It involves, amongst other things:- generalised mental and social alienation... a direct by-product of capitalism, the shift to high-tech capitalism (broadly more stationary, less fat-consumptive work but just as tiring), appalling occupational health in general, increasing 24-hour work and night-shifts that disrupt eating patterns, an ongoing inability (despite 'Jamie Oliver') to promote childhood health over cost-cutting in LEA budgets, lack of a culture of communal exercise.