In his first speech on public health since his appointment, Lansley this week revealed plans for a new Public Health Service, the details of which will be outlined in a White Paper in the autumn.
The government plans a "whole new approach that focuses on behaviour change; and which goes beyond constraining the supply of illegal drugs, alcohol and tobacco".
The coalition wanted to create a new responsibility deal between government and business built on shared social responsibility and not regulation, he said.
Lansley also noted in his speech to the UK Faculty of Public Health's annual conference that in many cases he would be unable to legislate because of EU rules.
"It's not about good food or bad food because that way you just close companies out," he said. "It's actually about a good diet or bad diet, good exercise or lack of exercise. It's about people having a responsibility."
The speech was an important landmark in moving on the health agenda, said FDF communications director Julian Hunt. While many subjects for discussion between government and the industry would remain the same, "the quality of the conversation will be better".
"We agree that in complex debates such as obesity the best solutions will be delivered through a shared social responsibility and not state regulation," he added.
It is still not clear when the public health remit of the Food Standards Agency will be moved into the DH.