By Laura Cummings BBC News Online business reporter

From the lengthening queues at slimming clubs, to the raft of celebrity-led fads, it is now almost a prerequisite to be following some kind of diet - or "eating programme" as they are now fashionably known.

And while the global economy's woes continue, the diet business is one industry that shows no signs of slowing.

I was going to try and be more sensible, but sadly comfort eating has taken hold Katie Hamilton, CBBC

Click here to read about celebrity diets

There are no official statistics for spending on diet products, but estimates vary from $40bn to $100bn in the US alone - more than the combined value of the government's budget for health, education and welfare.

But concerns are growing that this very industry is fuelling our rising obesity levels - after all, it would be a very short-lived business if we all succeeded first time.

Rising commodity

The body has long been viewed as a commodity.

But as obesity levels in the West soar, its cash-generating potential has never been so great for food companies.

Low fat food is at best confusing, at worst deceptive Paula Franklin Lighten Up

The same manufacturer can now feed us the ever-increasing pre-packaged meals and snacks that have come to characterise our supermarket shelves, while producing a growing range of "low fat/sugar/starch" varieties.

Ultimately, the companies' bottom line is a financial one - and they're rather hoping this bottom does look big.

New year, new profit

A survey from Norwich Union Healthcare suggested that just one month after pledging to be "firmer, fitter and healthier", half of Britain's new year resolution makers are - unsurprisingly - still in the same shape.

REASONS FOR FAILURE

Lack of will power Too busy with work and family Too expensive Lack of support from friends and family Source: Norwich Union

The good news for the diet industry is that in the process these would-be slimmers have shed £335m on their attempts.

Norwich Union describes the result as a "will power deficit", blaming lack of motivation, busy lifestyles and expense as reasons for their downfall.

However, research indicates that it is not will power, so much as having the odds stacked against them.

No industry actually benefits from us actually eating healthily for a sustained period of time.

Quick fixes

The gain to slimming magazines, manufacturers, even the "allergy clinics" that supply you with costly supplements for a sudden intolerance to spinach, are not hard to fathom.

Weight Watchers has helped millions lose weight

"[Dieting] is a business with enormous financial interest in making sure it continues," says Paula Franklin, a medical practitioner and general manager of "Lighten Up", a group aiming to help people slim without dieting.

"Even those companies that appear to help are not.

"Low fat food is at best confusing, at worst deceptive."

Ms Franklin argues that once again it is our cash-rich, time-poor way of life that fuels the paradox.

"We are an impatient society. Dieters want to see change quickly."

Necessary evil?

The National Obesity Forum (NOF) is less adverse to the industry.

"I feel very strongly that people should be doing something about their weight," says Ian Campbell, a spokesman for the NOF.

All this abundance, linked to a culture of slimness, makes people go crazy around food Susie Orbach Psychotherapist

But he added that the danger in diet food was that it can be "misleading" - "low fat", for example, often means "high sugar".

"It can make people dependent on a particular brand," added Mr Campbell - exactly the kind of success the Weight Watchers of this world are banking on.

With everything from bread, to soup, crisps and "pointed" sweets, you could stock an entire parlour and fridge with Weight Watchers products.

Lasting legacy

Susie Orbach, the well-known psychotherapist and author of "Fat is a feminist issue", is leading a campaign to challenge the diet industry and even proposing legal action against Weight Watchers.

"All this abundance, linked to a culture of slimness, makes people go crazy around food," Ms Orbach says.

"The same food companies segment the market - their motivation being only the delivery of profits."

"Weight Watchers is owned by Heinz - it has to fail, otherwise how would it make money?"

Weight Watchers was keen to point out that it is only the food business that is owned by Heinz, not the slimming club.

A spokeswoman for the meetings business says its aim is "to take the guilt away from eating".

"It teaches you to make decisions and these are designed to be for the long term."

Ms Orbach is working with fashion designers, shops and the food industry to challenge the now-ingrained "mono imagery" she says has gripped western society.

Her goal is to ensure dieting, and the profit it delivers, "isn't passed on to the next generation".