I wrote recently about how the nutrition "facts" we used to believe decades ago have changed. Even a study done last week will be refuted by a study this week. It's downright confusing. So I began to think: Wouldn't the most valuable advice be that which has stood the test of time? Combing through years of nutritional literature, I found some practical advice that holds true. If you are looking for guidance you can count on now and in the future, start with these rules.
Choose a variety of food
Let's be honest: There is no one superfood that can provide your body with the 40 nutrients that it requires. Variety is necessary to ensure you'll get the protein, carbs, fat, vitamins and minerals needed for good health.
From 1980 to 1995, the Dietary Guidelines for Americans included the advice to "eat a variety of foods." The 2015 Dietary Guidelines still say to "choose a variety of nutrient-dense foods across and within all food groups."
So what about popular eating plans that cut out major food groups — such as vegans avoiding milk and paleo dieters skipping grains? Can diets be healthy if they lack "all food groups"? There are many ways to mix and match foods to create a plan that provides enough variety to meet nutrient needs, but it has to be done right. Want to know whether your diet measures up? See a dietitian for an assessment to know for sure.
Eat your vegetables
Since the first U.S. Agriculture Department food guide appeared in 1917, the message to eat "vegetables and fruit" has been a mainstay, and the scientific research on the importance of vegetables has strengthened over time.
Studies link vegetable and fruit consumption with a reduced risk of developing Type 2 diabetes, high blood pressure, heart disease, obesity, dementia and certain types of cancer. Nutritional guidelines suggest you fill half your plate with vegetables and fruit at every meal. Plus, they are totally versatile and taste so good.
OK, so what if you just don't like vegetables? Here's the thing: With hundreds of options to try, there's bound to be something you enjoy. Try them in different ways to pique your palate: roasted to bring out their sweetness, raw to keep their crunch, in salads with delicious dressings. Don't give up until you find something you like, because the advice to eat veggies isn't going away.
Get enough fiber
Fiber-rich foods were recommended in the 1980 Dietary Guidelines for Americans to avoid constipation and reduce colon cancer risk.
Fast-forward almost 40 years and the advice remains the same. In addition to colon health, we also know that adequate fiber is vital for preventing heart disease and Type 2 diabetes. But just like in 1980, we're still not getting enough of this vital nutrient. The average American gets just 16 grams of fiber per day but should aim for 25 grams (women) to 38 grams (men).
Fiber-rich foods you can add to your diet include vegetables, beans, lentils, nuts, seeds, bran cereals and whole grains. Just a cup of raspberries or a half-cup of lentils will add eight grams of fiber to your day. Easy!
Say no to junk food
As early as the 1940s, the term "junk food" was used in the media as a negative way to describe foods such as cake, candy and soda. It linked those foods to health problems.
The 1979 USDA food guide "Food: The Hassle-Free Guide to a Better Diet," was the first version to add a category recommending moderation for foods that provided calories from sugar and fat but had little nutritional value.
It's safe to say that a healthy diet will never be built on cake and ice cream. And other than the ridiculously named Cookie Diet (a low-calorie diet that includes specially formulated cookies), there are no fad diets based on eating more junk food. Chips, candy and similar treats do not provide significant nutrients to the body, and overconsumption is linked to increased disease risk. That's not going to change.
Be careful with alcohol
Since 1980, the Dietary Guidelines have advised that if you drink alcohol, do it in moderation. What is moderation? It means no more than one drink a day for women or two drinks a day for men. And no, you can't save it up and consume seven to 14 drinks on the weekend. One drink equals 12 ounces of beer, 5 ounces of wine or 1 1/2 ounces of liquor such as vodka.
Alcohol carries the risk of dependency, and excess consumption is linked to liver damage, obesity and an increased risk of certain cancers. So the best advice is if you don't drink, don't start. And if you do drink, practice the Dietary Guidelines' definition of moderation. Like junk food, there won't be a time when alcohol becomes health food.
Cara Rosenbloom, a registered dietitian, is president of Words to Eat By, a nutrition communications company specializing in writing, nutrition education and recipe development. She is the co-author of "Nourish: Whole Food Recipes Featuring Seeds, Nuts and Beans."