Ian Watson, the chairman of the Local Authority Caterers' Association, told MPs the detailed rules, published last Friday, were unnecessary.
"We are all professional cooks and, with respect, we do not have to be told how to boil and how to steam," he told the Education Select Committee.
Beverley Baker, the vice-chairman of the association, added: "We want as much as anybody to encourage children to eat healthily and to have cooking skills."
The government guidelines set down national nutritional standards for school dinners and are aimed at encouraging a healthier diet.
Caterers are told to trim fat from meat, bake meat on a rack, and to steam or poach fish. They are told to boil potatoes in the minimum amount of water, and avoid glazing them with butter.
Heart disease experts welcomed the guidelines, saying school dinners contained too much sugar and too much fat.
Another caterer, Pat Fellows, told MPs school dining halls discourage children from eating. "The food and the standards [in school canteens] are excellent, but the ambience of the dining room remains old-fashioned. I would urge the Government to put in some investment," she said.
"Our customers are used to McDonalds fast food restaurants and we can't preventthem going out if our dining rooms are old-fashioned, dour, sad places. If we are going to encourage nutrition we need to have the right ambience to attract customers."
She said fewer and fewer children were able to cook. For many children, school dinners were their only hot meals eaten at a table. Yet under the government guidelines, there is no requirement to serve hot meals every day.
Imogen Sharp, director of the National Heart Forum, told the Select Committee: "If our children were learning how to cook at school, Delia Smith's How To Cook book would not be a best seller. If you cannot cook an egg in adulthood there is something seriously wrong in our classrooms."
THE GOVERNMENT GUIDELINES
Bread, cereals and potatoes
n Chips, fried or roast potatoes no more than three times a week
n Rice and pasta at least once a week
n Pizza no more than once a week
Fruit, veg and salad
n Baked beans no more than once a week
n Fresh fruit at least twice a week
n Fruit in dessert at least once a day
Milk and dairy produce
n Must be part of every meal
n Cheese as a main course no more than twice a week