Food products should be labelled using a "traffic light" system to provide consumers with easily understandable information on fat content, MPs are set to recommend.
In a hard-hitting report to be published in the next few weeks, the health select committee will say that the cost of obesity may have risen to £4.9bn a year. The committee will criticise the government for failing to make public health a priority issue across government.
They are expected to recommend that mandatory "traffic light" labelling should replace the nutritional labelling system, which has been described as "gobbledygook" by committee sources.
The committee consensus is also backing a ban on junk food advertising on children's TV if the industry fails to introduce an effective voluntary code shortly - a move that is being vociferously opposed by food manufacturers.
The committee is still looking at definitions of children's television, issues of product placement, and whether the regulator can order the advertising industry to market healthy products on TV.
Another option being considered is for school governors to have clearer powers to ban junk food machines in schools. The report will also recommend imaginative school exercise schemes, similar to those in Colorado where pupils are given pedometers to measure how far they walk each day.
The MPs, with the help of special advisers, have tried to update the cost of obesity last measured by the National Audit Office in 2001. The committee's researchers have calculated the NAO report may have underestimated the cost by between 27% and 40%.
That report, drawing on 1998 figures, put the cost of obesity at £2bn a year, and to the health service in treatment costs at £1.5bn.
The report suggests obese adults are cutting nine years off their life expectancy.
The year-long study is probably the most substantial single work on the British obesity crisis produced for a generation and follows visits to the US and Scandinavia.
One committee source said the government was "running scared" for fear of what the committee might propose. The report is expected to point out that the government first promised a food action plan in 2002. The plan was delayed due to interdepartmental inertia and is due to be published tomorrow by the chief medical officer, Sir Liam Donaldson. His report will recommend children exercise four or five times week.
In an attempt to head off criticism, the health secretary, John Reid, has announced he is planning a public health white paper in the summer. Ministers will want to deflect the criticisms in the all-party select committee report by describing it as a contribution to the white paper, but some committee members are minded to attack the government for failing to get a grip on the crisis earlier, and accusing ministers of running scared in the face of a powerful food industry lobby determined to head off regulation.
Mr Reid will back clearer labelling. He has also been in discussion with industry about cutting salt content in its products voluntarily.
The food industry has told the committee it wants to be part of the solution to the obesity crisis and that none of its products is inherently harmful if consumed in moderation. It will resist any ban on food advertising for children. The industry spends £400m a year on advertising.
The report will also underline the extent to which the obesity crisis is a crisis for the poor and the socially excluded.
