A food fight is developing over changes to Canada's longstanding guide to healthy eating.

Health Canada is set to release a new version of Canada's Food Guide, the first update to the bible on nutritional standards in 14 years.

Health Canada's Mary Bush, who is overseeing development of the new guide, says it will reflect the most up-to-date science on nutrition.

The revised guide will contain more specific information on portion sizes following complaints the old version was too confusing, Bush told The Canadian Press.

Health Canada has taken nearly two years to develop the new guide after consultations with advisory committees that included dietitians, food industry representatives and other stakeholders.

One of the concerns that came up was that the current guide can be confusing, especially when trying to decipher what a "serving" is.

The new guide -- which cost $1.5 million to develop and print -- will be age- and sex-specific.

It will dish out pointers on how many servings in each of the four food groups should be eaten daily by pre-schoolers through to seniors.

But critics are already panning a draft version of the new eight-page guide obtained by CP.

Dr. Yoni Freedhoff, medical director of Ottawa's Bariatric Medical Institute, told CP he is concerned the updated version might send the wrong message.

The guide is based on a 1997 nutrient database which Freedhoff says is an out-of-date resource that underestimates the number of calories in foods that have swelled in size over recent years.

He also questioned a reduction in the number of fruits and vegetables.

The new version recommends four to nine daily, depending on age and sex, down from five to 10 in the old one.

Bush says misconceptions that emerged with the draft guide will be cleared up when the final version of the guide is released.

Obesity Canada President Dr. David Lau says critics should bear in mind the food guide is meant for Canadians of all shapes and sizes.

"There are individuals who are underweight as well as individuals who are overweight," Lau told CTV Newsnet.

"For the critics who comment on the fact that perhaps the recommendations don't go far enough in terms of recommendations on portion sizes, that may be somewhat misleading."

When the guide refers to a portion, that means about the size of a small fist, he pointed out.

"So when we talk about having nine servings of fruits and vegetables, we are talking about maybe nine small cups of fruits and vegetables," Lau said.

Rejecting criticism that eating less fruits and vegetables is poor advice, Lau said the new guide aims to clarify proper intake.

"I think we have to take that into consideration the total amount of food, so we are not just focusing on fruits and vegetables," Lau said.

"Because in the past the concern was that if we are talking about recommending five to 10 servings of vegetables and people if they don't understand what a serving size is, they can gain actually weight by eating 5 to 10 servings of vegetables a day along with other things."

The new guide will also give guidance as to the calories and salt content that foods contain so that Canadians will be better educated on what comprises a balanced diet.

With files from The Canadian Press