Americans should strive to stay trim by eating a varied diet that emphasizes starch and fiber, and should limit their intake of fat, sugar, salt and alcohol, according to new government guidelines released yesterday.

The advice -- a common-sense approach to food almost identical to that issued five years ago -- is the work of a nine-member committee sponsored by the Agriculture Department and the Health and Human Services Department.

Consumer groups praised the guidelines' similarity to the old ones, since the 1980 version provoked pressure upon the government from the meat, dairy and egg industries to back down on its warnings against saturated fat and cholesterol.

"These guidelines are extremely important, because they establish the conventional wisdom," said Michael Jacobson, executive director of the Center for Science in the Public Interest.

Jacobson faulted the recommendations for not highlighting research that links high-fat, low-fiber diets with cancer. Block said the panel "debated it a considerable amount of time, and in the final analysis, decided they needed to know more before they drew that link."

The meat and egg industries issued statements supporting the new guidelines, which differ from the 1980 version in emphasizing the nutritional value of meat and explaining that egg yolks, but not whites, are high in cholesterol.

"They are guidelines for the total diet. They do not suggest that any single food be eliminated," said Agriculture Secretary John R. Block. "They are general and directional, not rigid and quantitative."

Block said the recommendations are aimed at healthy Americans, but are especially appropriate for anyone at higher-than-average risk of developing chronic disease. Risk factors include obesity, diabetes, a family history of heart attacks, high blood pressure, high blood cholesterol levels, and cigarette smoking.

The guidelines include:

*Eating foods from all major groups: fruits and vegetables, grains, dairy products, and protein (meat, fish, eggs, beans and peas.)

*Avoiding large doses of vitamin or mineral supplements (such as Vitamin C or calcium).

*Maintaining weight in the desirable range for height by exercising and eating foods high in nutrients but low in calories. Being overweight increases chances of high blood pressure, heart disease, stroke, diabetes and some cancers.

*Reducing saturated fat and cholesterol in the diet, by using skim or low-fat milk, limiting egg yolks and organ meats, and cutting down on saturated fats like butter, cream and lard. Foods should be broiled, baked or boiled, rather than fried.

*Choosing foods that are good sources of fiber and starch, such as whole-grain breads and cereals, fruits, vegetables, and dry beans or peas, rather than those high in fat and sugar.

*Cutting down on sweets to reduce tooth decay.

*Limiting salty foods, cooking without salt, and adding little or none at the table.

*Drinking no more than one or two alcoholic drinks a day, and none at all during pregnancy.

The recommendations stop short of suggesting numerical limits on the amount of fat or the number of eggs Americans should eat. Some members of the panel apparently favored that approach, but the committee decided that there was too much variation in individuals' metabolisms, risk factors and life styles to warrant it.

"We cannot determine for everybody in this country how many eggs a week they can have," said Suzanne Harris, administrator of the USDA's Human Nutrition Information Service.

Consumers can get a free copy of guidelines by writing to Dietary Guidelines, Consumer Information Center, Pueblo, Colo. 81009.