REMEMBER THE OLD days, when Rhoda wondered how she could lose 10 pounds before her 8 o'clock date? She told Mary Tyler Moore that cottage cheese wouldn't help depression, chocolates would help depression.

Dressed in a sweatshirt, wielding high-calorie one-liners, she summarized the plight of moderately overweight America. After all, what's six cookies in the face of 20 pounds?

What, indeed. Statistics tell us that nearly all of us diet at least once in our lives, that a member of our family is probably dieting right now. And most of us will fail -- so much so that "failing" might be a synonym for "dieting."

At the new year, when everyone approaches dieting with a zeal to equal 52 Monday mornings combined, perhaps it is more pertinent to recognize weakness rather than strength. The new year is an appropriate time to examine the tips and trials of famous food freaks. From Rhoda, aka Valerie Harper, to the man on the street, knowing weaknesses is the best way to overcome them, isn't it?

Valerie Harper has weaknesses. She's known herself to sit down and polish off a box of cookies. Summoning all restraint, she would virtuously wait 30 minutes before hitting the ice cream. "This eating was the one place I could be naughty," Harper recalls.

Because "it's very difficult to look at yourself in a leotard" when you're fat, Harper says, she's one more convert to the physical fitness school of permanent weight loss. In fact, Washington is one of her favorite places -- to run (on the Mall) and to watch (professionals "walking to work in their Nikes").

Now, she says, "I have learned that my choice isn't always what I wanted. I may want Haagen-Dazs, but I choose cottage cheese."

Dr. Maria Simonson, director of the Johns Hopkins Health, Weight and Stress Control Clinic, says that we fail because we set unreasonable goals. It's more than wanting to lose too much too fast. Our expectations are irrational: "that once you lose weight you'll have men flock to you, you'll get your husband back, get a big pay raise . . . that a great, glamorous life will open up for you and you'll look 10 years younger."

"Before you can really lose weight," she continues, "you have to assess the total person," to examine the reasons for being overweight before trying to rectify the situation.

The holiday season presents both positive and negative stimuli for overeating. First, the food is usually delicious and fattening, so one eats more of the food that one shouldn't. Second, says Simonson, people are usually rushed, disorganized and under unusual stress, which means they aren't planning meals or spending much time to maintain their diets.

Restraint. It isn't easy to have. Self-proclaimed "top hog" Calvin Trillin didn't have restraint, so he married it. With "nagging, ridicule and verbal abuse," his wife, Alice, manages her husband's weight. She restricts him to an unreasonable three meals a day, he says in his book, "Alice, Let's Eat." Although this professional eater and frequent contributor to the New Yorker magazine says he is "not a picky eater," he does refuse to eat a "certain kind of Ethiopian bread."

Through bites of leftover Chinese carryout food, Trillin says that for the New Year he resolves to "continue in my passive moderation and restraint unless I can find something good to eat."

Like Rhoda, Trillin reflects eating a l'americaine. "I'm sometimes on a half diet, but almost never on a complete diet." Alice will caution him against eating when he starts to gain weight.

By telling him he looks terrible?

"Terrible would be one of the words she would use," he says.

Trillin travels often, however, and Alice isn't always around to chastise him. In those situations, Trillin follows a few rules. First, he says, you never gain weight when you snack. Next, you never gain weight when you eat standing up ("If you ate sausages sitting down . . . even I know that would never work"). Eating off other peoples' plates isn't fattening, he says, because God is so happy to see them sharing that he turns his head and doesn't count the calories. And cold air removes a quarter of the calories from food, so if you eat in front of an open refrigerator, you're golden.

Well, if Trillin's methods don't work, Pat Dinkelaker's method might. A registered dietitian, she teaches behavior modification techniques at Montgomery College and says that people just need to learn how to eat. If any of the participants in her behavior therapy class likes cookies, she says, "they have to learn how to eat cookies."

Decidedly anti-diet, Dinkelaker is convinced no one can lose weight by being given a list of foods he can or can't eat.

By behavior therapy techniques, one learns when, where and why he eats. He learns how to deal with the boredom, stress or fatigue that often trigger compulsive eating. Weight loss becomes individualized.

Because eating disorders are as diverse as the people who have them, an individual approach to weight loss is important. Executives who must cope with large business lunches and a sedentary lifestyle must approach weight loss differently than the housewife who is barraged with a tempting array of food advertisements and making sure there's no waste on the family dinner plates.

Like Simonson, Dinkelaker insists that people "get in trouble when they eat without thinking, when they don't plan. If you want to keep your weight off, you have to plan."

And for the new year, she says, anyone trying to lose weight should not be discouraged about "blowing his diet."

As soon as people give in to one temptation, she says, "they think it's open season. Then Monday comes again, then they get serious again." Better, she said, to take the ScarlettO'Hara approach by saying, "tomorrow is another day," and immediately return to the diet.

Weatherman Willard Scott agrees that no "diet" will help anyone lose weight. "It's got to be a way of life," he says enthusiastically.

Scott started his weight loss on Memorial Day weekend, a week before his vacation started. After "mulling it over for about 10 years" (and meeting author and high-carbohydrate dieter Nathan Pritikin on the Today Show), he changed his eating habits.

His downfall, says Scott, was cocktail hour. He'd drink Jack Daniels and "eat more munchies before dinner than most people would have in their diets all day long." The drinks primed him for a huge meal that was frequently meat and potatoes, among other things.

Pritikin "made a lot of sense," says Scott. He says he has given up "salt, butter and booze" (although he'll drink a little wine and beer). He still eats meat, but rarely beef, and certainly less than before.

"Anything you can juice, I juice," says Scott about a vegetable juicer that he owns and uses these days for modified cocktails. Instead of peanuts, he eats water crackers.

He insists he's never felt deprived on the diet. He is never hungry, dines well on minestrone, spaghetti primavera, veal and chicken. He gobbles up a type of hiker's mix that resembles "sweet feed" (a mixture horses eat). It's heavy on the oatmeal, light on the raisins and almonds and sprinkled with a little coconut. "I could eat bowls of it," he says.

Scott has lost 45 pounds since May, but isn't really worried about achieving any ideal weight -- which he estimates to be around 210 (he started at 285). "The thing is, it's fun. You get to a point where you really enjoy this stuff," he says.

In addition, Scott saves $30 to $40 a week not drinking and not eating so much meat.

When boredom with food is the only thing that stands between you and weight loss, the following recipes might help.

CHICKEN AND CAULIFLOWER (2 servings) 2 chicken breasts, skinned and boned 2 teaspoons flour 2 teaspoons olive oil 1 cup sliced mushrooms 2 tablespoons lemon juice 1 teaspoon minced garlic 3/4 cup chicken broth 1 cup parboiled cauliflower florets 2 teaspoons white wine 2 tablespoons chopped fresh parsley

Lightly coat chicken with flour. Heat olive oil in skillet and brown chicken. Remove from pan and set aside. Add mushrooms, lemon juice and garlic. Saute', stirring occasionally, until mushrooms are barely tender. Add broth and cook, stirring constantly, until mixture boils. Add chicken, cauliflower and wine. Turn to coat with heated sauce. Sprinkle with parsley just before serving. (275 calories per serving.)From "Weight Watchers 365-Day Menu Cookbook"

VERMICELLI WITH CRAB (4 servings) 2 tablespoons olive oil 1/2 cup sliced scallions 1 clove garlic, crushed 2 tomatoes, peeled, seeded and chopped (drained, canned plum tomatoes will do) 1/4 cup dry white wine 1 tablespoon lemon juice 1/2 pound flaked, cooked crab (or substitute other seafood such as scallops or leftover fish) 1/4 cup chopped parsley Salt and pepper to taste 4 cups cooked vermicelli

In a large skillet, heat olive oil. Add scallions and garlic and stir over medium heat about 2 minutes. Add tomatoes and wine. Stir until mixture boils and cook 2 minutes longer. Add lemon juice, crab and parsley. Season with salt and pepper. Spoon sauce over hot pasta. (260 calories per serving.)

BAKED APPLES WITH HONEY SNOW (6 servings) 6 baking apples, such as golden delicious 1/2 cup orange juice 1/2 cup fruity wine, such as rose or riesling 1/2 cup honey 1 stick cinnamon 11-ounce can mandarin oranges 1 egg white 1/4 teaspoon nutmeg

Core apples and pare off 1 inch of peel around the top. Arrange in a baking dish. In a saucepan, combine orange juice, wine, half the honey and the cinnamon stick (broken into pieces). Simmer until honey is dissolved and ingredients are blended. Pour this sauce over the apples. Bake at 375 degrees for 30 minutes. Drain mandarin oranges and spoon several sections inside each apple cavity. Baste with pan juices and bake 5 minutes more. While apples are baking, beat egg white until soft peaks form. Gradually add the remaining honey and beat until stiff. Blend in nutmeg. Serve with warm apples. (150 calories per serving.)

From "Entertaining the Slim Way," by Lou Pappas, (Addison-Wesley, $5.95).

NEW ORLEANS CHICKEN GUMBO (2 servings) 1 large chicken breast, skinned 2 ounces very lean pork 1/2 cup chicken stock 1 1/2 cups canned tomatoes with juice 1 cup chopped onions 3/4 cup diced green pepper 2 large cloves garlic, chopped 4 tablespoons lemon juice 2 tablespoons arrowroot 1 tablespoon thyme 10 drops hot red pepper sauce Salt and pepper to taste 1/2 cup uncooked scallops or shrimp 1 cup sliced okra 2 teaspoons file powder

Poach chicken in water to cover about 20 minutes. Cool and strip chicken from bones. Cut into small pieces. Set aside. Cut pork into bite-sized pieces. Brown in large heavy skillet and drain off any fat. Add chicken stock, 1/2 cup of the tomatoes, onion, green pepper, garlic and lemon juice. Stir in arrowroot. Add thyme and hot red pepper sauce. Season with salt and pepper. Cover and simmer for 30 minutes, stirring from time to time. Add chicken, scallops, okra and the remaining tomatoes and juice. Bring to a boil, lower heat and simmer 15 minutes. Add gumbo file' powder and stir, but do not boil. Serve in heated bowls over cooked brown rice. (314 calories per serving; 404 with 1/2 cup cooked, brown rice.)