The American Heart Association says to limit your consumption of fats and cholesterol. The American Cancer Society says to eat more fiber. The National Research Council says to watch out for fats, sugar, and salt. The American Diabetes Association says to eat regular meals so your blood sugar stays even.

The Food Police say if it tastes good, forget it! The U.S. Departments of Agriculture and Health and Human Services have incorporated virtually all but the “tastes good, forget it” rule into the Dietary Guidelines for Americans 2005 and even added some advisories of their own.

The Dietary Guidelines for Americans is a collection of sensible suggestions first published by the Departments of Agriculture and Health and Human Services (USDA/HHS) in 1980, with five revised editions since then (1985, 1990, 1995, 2000, 2005).

As the first chapter of the 2005 edition explains, the Guidelines lay out food and lifestyle choices that promote good health, provide the energy for an active life, and may reduce the risk or severity of chronic illnesses, such as diabetes and heart disease.

These suggestions are organized as nine standalone chapters, but for convenience’s sake — and because it seems logical — I’ve grouped them into three categories: “Weight Control,” “Smart Food Choices,” and “Keep Food Safe to Eat.”

Weight Control

During the past two decades, as the number of overweight Americans has bounced upward like a rubber ball, the incidence of obesity-related conditions such as Type 2 diabetes, high blood pressure, and heart disease also has risen. Three chapters in the new Dietary Guidelines (“Adequate Nutrients within Calorie Needs,” “Weight Management,” and “Physical Activities”) lay out some clear, um, guidelines.

Getting Nutritious Calories

Some foods provide lots of nutrients per calorie. Some don’t. The former are called “nutrient-dense foods.” The latter aren’t. As you may expect, the Guidelines recommend choosing foods from the first group to meet your calorie needs each day, while limiting the amount of:

• Foods high in saturated fat
• Foods high in trans fats
• Foods high in cholesterol
• Foods with added sugar
• Foods with added salt
• Alcohol beverages

In other words, stick to a balanced diet. No surprise there.

Managing Your Weight

To reach and keep a healthful weight, follow a few realistic rules:

• Evaluate your weight. The best test of who’s actually overweight is the Body Mass Index (BMI), a measure of body fat versus body lean mass (in other words, muscle) that can be used to predict health outcomes.

• If you need to lose weight, do so gradually. Forget the “lose 30 pounds in 30 days” jazz. Depending on how much weight you have to lose, your long-term goal needs to be losing about 10 percent of your total weight over a 6-month period. Losing 1⁄2 to 2 pounds a week is a safe and practical way of doing so.

• Encourage healthy weight in children. One unhappy fact is that overweight kids become overweight adults. Helping children stick to a healthy weight pays large dividends down the road of life.

• Check with your doctor before starting a weight loss diet. This advice is most important for women who are pregnant or nursing, for children, and for anyone — young or old — who has a chronic disease and/or is on medication.

Being Physically Active

When you take in more calories from food than you use up running your body systems (heart, lungs, brain, and so forth) and doing a day’s physical work, you end up storing the extra calories as body fat. In other words, you gain weight. The reverse also is true.

When you spend more energy in a day than you take in as food, you pull the extra energy you need out of stored fat and you lose weight. I’m no mathematician, but I can reduce this principle to two simple equations in which E stands for energy (in calories), > stands for greater than, <>

If Ein > Eout: Etotal = +W
If Ein< etotal ="">

It ain’t Einstein’s theory of relativity, but you get the picture! Even being mildly active increases the number of calories you can wolf down without gaining weight. The more strenuous the activity, the more plentiful the calorie allowance. Clearly, you need more calories for doing your daily physical work, simply moving around, or exercising.

After you decide to start moving, the Guidelines say, do it every day. How much should you do? Per the Guidelines:

• Most people will benefit from 30 minutes of moderate physical activity — such as a brisk walk — per day.

• To manage body weight and/or prevent gradual weight gain, make it 60 minutes of moderate-to-vigorous-intensity activity several days a week.

• To keep weight off, try 60 to 90 minutes of daily moderate physical activity.

• To reach true physical fitness, your regimen should include cardiovascular conditioning, stretching exercises for flexibility, and resistance exercises or calisthenics for muscle strength and endurance.

Not everybody can — or should — run right out and start chopping down trees or throwing touchdown passes to control his or her weight. In fact, if you have gained a lot of weight recently, have been overweight for a long time, haven’t exercised in a while, or have a chronic medical condition, you need to check with your doctor before starting any new regimen.

Smart Food Choices

Okay. So you have your weight goals firmly in mind and three, or four, or even seven times a week, you manage to Hup! Two, three, four at home, or in the gym, or on a walk around the block. The next task set forth by the Guidelines is to put together a diet that supports your new healthy lifestyle.

The Guidelines has five chapters designed to simplify your task: “Food Groups to Encourage,” “Fats,” “Carbohydrates,” “Sodium and Potassium,” and “Alcoholic Beverages.”

Perfect Plants

From the beginning, way back in 1980, the various editions of the Guidelines have recommended that you build your diet on a base of plant foods. Why? Because plant foods:

• Add plenty of bulk but few calories to your diet, so you feel full without adding weight.

• Are usually low in fat and have no cholesterol, which means they reduce your risk of heart disease.

• Are high in fiber, which reduces the risk of heart disease; prevents constipation; reduces the risk of developing hemorrhoids (or at least makes existing ones less painful); moves food quickly through your digestive tract, thus reducing the risk of diverticular disease (inflammation caused by food getting caught in the folds of your intestines and causing tiny out-pouchings of the weakened gut wall); and may lower your risk of some gastrointestinal cancers.

• Are rich in beneficial substances called phytochemicals, which may reduce your risk of heart disease and some forms of cancer.

For all these reasons, the Guidelines recommend that a basic 2,000 calorie daily diet include:

• 2 cups of fruit.
• 2.5 cups of vegetables (include dark green, orange, and starchy veggies, plus beans).
• 3 or more 1-ounce servings of whole grain products.

To protect your bones, the Guidelines advise washing down your plants with 3 daily cups of low-fat milk (349 milligrams calcium) or fat-free milk (306 milligrams calcium) or the equivalent amount of milk products such as cheddar cheese, which has 204 milligrams calcium per ounce.

Fats

Dietary fat (the fat in foods) is an essential nutrient. Infants need these fats to thrive, and the same cholesterol that may increase an adult’s risk of heart disease is vital to an embryo’s healthy development, triggering the action of genes that tells cells to become specialized body structures — arms, legs, backbone, and so forth.

Grown-ups, however, need to control fat intake so they can control calories and reduce the risk of obesity-related illnesses, such as heart disease, diabetes, and some forms of cancer. Overall, the Guidelines suggest that your adult diet derive no more than 35 percent of its calories from fat and no more than 10 percent of calories from saturated fat and that it deliver 300 milligrams or less of cholesterol a day.

To reach these goals:

• Most of your fat calories should come from foods such as fish, nuts, and vegetable oils that are rich in polyunsaturated and monounsaturated fats.
• Dairy products, such as milk, should be low- or no-fat (skim).
• Poultry and meat should be lean (yes, trim off that visible fat).
• With trans fats, less is always better.

Carbs

Carbs are your fastest source of energy, but the trick here is to get your carbs complex, which means from plant foods: fruits and vegetables and whole grains. The companion stratagem is to buy and prepare foods with little added sugar. Together, these two simple steps help control weight, provide vital nutrients, and — as the Guidelines slyly note — “reduce the incidence of dental caries” (cavities).

Salt and Potassium

Sodium is a mineral that helps regulate your body’s fluid balance, the flow of water into and out of every cell. This balance keeps just enough water inside the cell so that it can perform its daily jobs but not so much that the cell — packed to bursting — explodes. Most people have no problems with sodium.

They eat a lot one day, a little less the next, and their bodies adjust. Others, however, don’t react so evenly. For them, a high-sodium diet appears to increase the risk of high blood pressure. When you already have high blood pressure, you can tell fairly quickly whether lowering the amount of salt in your diet lowers your blood pressure.

But no test is available at this point for telling whether someone who doesn’t have high blood pressure will develop it by consuming a diet that’s high in sodium. Because limiting sodium intake to a moderate level won’t harm anyone, the guidelines advocate avoiding excessive amounts of salt.

Doing so helps reduce blood pressure levels for people who are salt-sensitive. What’s moderate use? According to the Guidelines, you should consume less than 2,300 milligrams (approximately 1 teaspoon of salt) of sodium per day. The easiest way to reach that goal is to choose and prepare foods with very little added salt.

At the same time, it pays to consume potassium-rich foods, such as (what else?) fruits and vegetables, because an adequate supply of potassium helps control blood pressure. By the way, moderating your salt intake has another, unadvertised benefit. It may lower your weight a bit. Why?

Because sodium is hydrophilic (hydro = water; philic = loving). Sodium attracts and holds water. When you eat less salt, you retain less water, you’re less bloated, and you feel thinner. Don’t reduce salt intake drastically without first checking with your doctor. Remember, sodium is an essential nutrient, and the Guidelines advocate moderate use, and not no use at all.

Alcohol

Telling someone to drink alcohol beverages in moderation sounds like Momand- apple-pie advice, right? Right. But — and you’ve heard this song before — what’s moderation, anyway? Laypersons (you and me, babe) may define moderate in terms of the effects that alcohol has on the ability to perform simple tasks, such as speaking and thinking clearly or moving in a straight line.

Obviously, if the amount of alcohol you drink makes you slur your words or bump into the furniture, that isn’t moderation. The Dietary Guidelines define moderate drinking as one drink a day for a woman and two drinks a day for a man. Aha, you say, but what’s one drink? Good question. Here’s the answer:

• 12 ounces of regular beer (150 calories)
• 5 ounces of wine (100 calories)
• 11⁄2 ounces of 80-proof (40 percent alcohol) distilled spirits (100 calories)

Dietary Guidelines for Americans 2005 (Washington, D.C.: U.S. Department of Agriculture, 2005)

Some people shouldn’t drink at all, not even in moderation, including people who suffer from alcoholism, people who plan to drive a car or take part in other activities that require attention to detail or real physical skill, and people using medication (prescription drugs or over-the-counter products).

Keep Food Safe to Eat

In 2000, the Centers for Disease Control and Prevention (CDC) estimated that spoiled or contaminated food causes about 76 million illnesses — 325,000 of them serious enough to require hospitalization — and 5,000 deaths every year in the United States.

Three years later, the USDA blamed Salmonella organisms alone for more than 3.5 million American stomachaches — or worse. Clearly, keeping food safe to eat is an important goal. To do that, here’s an equation any careful cook can rely on: Clean stores + clean hands + clean kitchen + proper storage + proper temperature = safe food That’s the short version of the Guidelines’ guidelines.

Right now, raw is in but not — as the Guidelines explain — necessarily healthful. To reduce your risk of picking up an icky bacterial disease along with dinner, the Guidelines advise avoiding raw (unpasteurized) milk or any products made from unpasteurized milk; raw or partially cooked eggs or any dish containing raw eggs; raw or undercooked meat and poultry; unpasteurized juices; and raw sprouts.

Life is not a test. You don’t lose points for failing to follow the Dietary Guidelines for Americans 2005 every single day of your life. Nobody’s perfect, and the Guidelines are meant to be broken — once in a while. For example, ideally you should hold your daily intake of dietary fat to 20 to 35 percent of your total calories.

But you can bet that you’ll exceed that amount this Saturday when you stroll by the buffet at your best friend’s wedding and see Camembert cheese (70 percent of the calories from fat), sirloin steak (56 percent of the calories from fat), salad with Thousand Island dressing (90 percent of the calories from fat), and whipped cream cake (I can’t count that high).

Is this a crisis? Should you stay home? Must you keep your mouth shut tight all night? Are you kidding? Here’s the Real Rule: Let the good times roll every once in a while. After the party’s over, compensate. For the rest of the week, go back to your exercise regimen and back to your healthful menu emphasizing lots of the nutritious, delicious, low- or no-fat foods that should make up most of your regular diet.

In the end, you’re likely to have averaged out to a desirable amount with no fuss and no muss and be right in line with that headline from the first page of the 2000 Guidelines that I mention at the beginning: “Eating is one of life’s greatest pleasures.” Amen to that.