Addressing the all-party pharmacy group, Mr O was able to sum up his two-stone weight loss pretty succinctly: "I had to go and answer to somebody."
That somebody was his local pharmacist, John Gowes, who has spent the past year trying to reduce the body mass of 150 Coventry people. About 69% of the group has lost weight (5% of their body mass on average) and kept it off for a year. The scheme cost the primary care trust (PCT) about £20,000.
The method is not complicated. John meets up with participants on a regular basis and provides advice on "subtle lifestyle changes", while taking measurements to see what impact these alterations are having on the individual's health.
In Mr O's case, it meant that he was able to have his knee operation within three months of starting the programme, and the local NHS had to pay for one, rather than 12, sets of physiotherapy afterwards.
Mr O was trimmer. John was passionate. The audience was fascinated. The health select committee MP wanted to know whether it could be rolled out nationally. If anyone was battling the desire to yell "nanny state", they did a good job of biting their tongue for 90 minutes.
Presumably the assembled audience of pharmacists and PCT executives is not only au fait with the findings of the Foresight report but also has frontline experience of the grim landscape it paints.
If current trends play out, over half of us will be obese by 2050, at a cost of £10bn to the NHS. We will become so rather blindly, the report suggests, let down by a homeostatic biological system that cannot cope in a world where the pace of technological revolution outstrips human evolution. People will gain weight on a "largely involuntary" basis, by being "exposed" to a modern lifestyle.
We need help from the people who understand this - the John Goweses of our communities, who appreciate just how hard it is to lose weight and keep it off.
A lexicon of powerlessness is deployed throughout the report. One of the most telling sentences reads: "Although behaviour has historically been considered as a product of free will, it is increasingly recognised as being constrained by individual circumstances."
We are depicted as victims of numerous overwhelming forces, not least biological ones.
Research has shown that the sight, smell, palatability and availability of food can increase our appetite to such an extent that it overwhelms innate control mechanisms. We are simply not designed to respond to abundance. And we live in an "obesogenic" environment that conspires against us, with its low-cost convenience foods and fast-food outlets near schools.
At times, it is hard to recognise the besieged generation the report depicts. Presumably this is the point: we are victims of our own success in stockpiling food and reducing the need for physical exertion.
The price of this success is heavy, not just in cost - the government has allocated £372m to its anti-obesity strategy - but also in terms of privacy. For all Gordon Brown's protestations that it is "not the role of government to tell people how to live their lives", and that "maintaining a healthy weight must be the responsibility of individuals first", the government knows that it is going to have to do some serious chivvying. In the coming years, MPs, GPs and schools, to name but three, are going to be taking great interest in what is on our plates.
The Foresight report is unapologetic about this, a stance that goes hand in hand with a notable reluctance to apportion blame to individuals that is evident even in the sentence construction. Those that make unhealthy choices are experiencing "psychological ambivalence".
Gordon Brown wants to make sure that people "have access to the opportunities they want and information they need in order to make choices and exercise greater control over their health and their lives".
Yet, put basely, the strategy is partly about reducing the choice and control of individuals. Planning regulations are to be amended so that local authorities are able to reduce the number of fast food outlets in certain areas. The government expects that, even with information and opportunity, we will make choices that are bad for us. That's why it is looking at financial incentives to reward weight loss. If you want an indicator of the shape of things to come you could look at the evidence for reducing alcohol consumption (page 76 of the report). Provision of education and information for the public languishes at the bottom of the league table. It is sticks that work: price increases and restrictions on the purchaser's age and opening hours, plus penalties for drink drivers.
Foresight believes a national debate is required to decide whether certain policies are socially acceptable. Yet everything about both the report and the strategy implies that, left to the public, obesity will become the norm.
Perhaps the drivers towards obesity really are too much for Mr O and the millions of others like him, and we need nannies like John Gowes. Perhaps it will be obeisance to nanny, and not obesity, that is the norm in 2050.
