First we were told to limit eggs to four a week, then to limit wine to a glass or two a day. Now a study indicates we should draw the line at three cups of coffee.

The study, which included more than 100,000 members of Kaiser Permanente Medical Center, showed that four or more cups of coffee a day increase the risk of heart attack by 40 percent.Dr. Arthur L. Klatsky, director of the study, says the three-cup-a-day guideline applies to those at high risk of heart disease (such as middle-age males, or those with elevated blood cholesterol or blood pressure). There is no established limit for others. Klatsky added that for people in the high-risk group, the limit should also include decaffeinated coffee.

Nutritionists generally resist setting specific limits on particular foods because people's dietary needs can differ widely. But there are a few well-established limits that will help you know if you're exceeding moderation.

-Animal protein. The American Heart Association, U.S. Department of Agriculture (USDA) and U.S. Department of Health Services (HHS) agree that most adults can get adequate protein from 6 ounces (cooked weight) of seafood, poultry or lean meat per day. A half-chicken breast is about three ounces.

Limiting animal protein to this amount will help keep your dietary cholesterol in check; 300 milligrams is the American Heart Association's daily limit. Substituting cooked dry beans for animal protein helps cut cholesterol intake further.

-Eggs. Actually the limit is on egg yolks. The recommendation from the American Heart Association is four yolks per week. (Those with high blood cholesterol would be wise to eat less or none.)

-Alcohol. The USDA and HHS advise an alcohol limit of one drink a day for women, two for men. A drink is defined as 12 ounces of regular beer, five ounces of wine or 1 1/2 ounces of distilled spirits (80 proof).

-Fats and oils. We've all heard the advice to keep fat below 30 percent of calories. It's tricky to advise a set number of teaspoons of oil or margarine since fat creeps into the diet from so many other sources.

Also, your caloric allowance determines your fat allotment and this depends on age, sex, body size and activity.

Assuming you get little fat from other foods, the Daily Food Guide from the California Department of Health Services advises six to eight servings of fat daily.

The American Heart Association recommends five to eight - consisting of unsaturated fats, of course. A serving equals one teaspoon of margarine or oil; two teaspoons of peanut butter, mayonnaise or salad dressing; one tablespoon of chopped avocado or olives, nuts or seeds.

-Sodium. Guidelines vary. The American Heart Association recommends 1,000 milligrams of sodium per 1,000 calories, not to exceed 3,000 milligrams. The National Academy of Sciences espouses a maximum of 2,400 milligrams.

While keeping a lid on these foods and beverages, remember to include each day: two servings of calcium-rich foods, six or more servings of breads and cereals, and at least five of fruits and vegetables.