When most of us hear “diet,” we think of a four-letter word meaning something we must suffer through — a short-term means to a desired outcome.
We imagine our future selves leaner, sexier, happier. And so we grin and bear it as we choose from among the many, many options available. There are Atkins, South Beach, The Zone, the grapefruit/cabbage soup/banana mono diets, the Paleo diet and its popular spin-offs, and dozens more.
As anyone who has tried them can tell you, these diets usually lead to merely short-term success, if any at all.
But a “diet” can also be a set of guidelines — a way to see how your eating measures up to a healthy standard.
Creating a Better Guideline
In 1995, the United States Department of Agriculture (USDA) created the Healthy Eating Index (HEI), which rated adherence to the 1995 U.S. Dietary Guidelines. Were the guidelines making people healthier? One team of researchers found the answer was no.
Dr. Walter Willett, chair of Harvard’s Department of Nutrition, and colleagues reported in a 2002 issue of the American Journal of Clinical Nutrition that the HEI failed to predict chronic disease risk and mortality.
The [new diet] stressed that the quality of the foods we eat is much more important than the percentages of macronutrients themselves.
In other words, following the government’s guidelines did not improve health risk factors.
Willett suspected that he and his team could do better. Armed with the best research available at the time, they created their own rating system, dubbed the Alternate Healthy Eating Index (AHEI).
Rather than promoting a diet lower in total fat and higher in carbohydrates as the HEI did, the AHEI stressed that the quality of the foods we eat is much more important than the percentages of macronutrients themselves. Whole grains are better than refined carbohydrates, it said, and heart-healthy mono- and polyunsaturated fats are healthier than saturated and trans fats.
The AHEI also distinguished between red meat and poultry/fish intake, giving a higher score to those who got their protein from the latter or from plant sources. In a follow-up study published in 2006 in the journal Public Health Nutrition, the AHEI outperformed the HEI two to one for predicting cardiovascular disease and other major chronic disease risk.
In 2010, Willett and a new team of researchers updated the AHEI to reflect the latest nutrition science. In the face of a growing body of compelling research, the USDA has also amended both the Dietary Guidelines and its own HEI. Changes in the 2015 Dietary Guidelines included keeping added sugar to less than 10 percent of calories, and the removal of the restriction on the percentage of calories from total fat (the guidelines now recommend no more than 10 percent of calories should come from saturated fat).
A 2016 post published on the Harvard School of Public Health’s website commends the 2015 Guidelines for bringing its recommendations more in line with the research community’s findings, though it also points out a few areas where the USDA still needs to improve.
Putting Diet Research Into Practice
Although the AHEI-2010 was designed as a research tool for use by scientists and public policy makers, it can also serve as a useful guide for individuals who want to clean up their diets and avoid lifestyle-related diseases. Harvard’s Healthy Eating Plate is a good, basic visual representation of the AHEI-2010 criteria, but as a health coach I know that people want details.
To that end, here is a list of the criteria it uses to score the quality of a person’s diet, in a format you can use every day:
Eat More of These
Vegetables Your goal should be to consume five or more servings of vegetables every day, and the more variety you can work into those servings the better. I advise my clients to “eat the rainbow” every day, because different colored vegetables offer different micronutrients.
Fruit The AHEI gives a maximum score for eating four or more servings of whole fruit each day. Frozen fruit is just as healthy as fresh, but if you eat canned fruit, know that it has probably lost some of its nutritional value and be sure it’s not packed in sugary syrup or a sugar-added fruit juice.
Whole Grains The recommended intake for whole grains is 75 grams for women and 90 grams for men, or two to three servings each day. Whenever possible, these should be intact whole grains, not processed whole grain products like pasta and bread.
Some examples of whole grains are brown, black or red rice; steel cut or old-fashioned oats; quinoa; millet; bulgar (cracked wheat); buckwheat and barley. The Oldways Whole Grains Council is a great resource for learning how to cook with whole grains.
Nuts and Legumes Nuts and legumes are a great source of plant protein and healthy fats. The AHEI recommends eating at least one serving every day.
Polyunsaturated Fats and, especially, Omega-3 Fatty Acids One of the strongest recommendations of the original AHEI was to replace trans fats and saturated fats with healthier unsaturated fats. In 2010, Willett’s team took this a step further and added the recommendation to consume at least 250 milligrams per day of the long-chain omega-3 fatty acids, EPA and DHA.
Healthy polyunsaturated fats are found in nuts and plant oils, like olive and canola oil, and fatty fish and fish oil or algae-derived supplements are your best bet for long-chain omega-3s.
Eat and Drink Less of These
Sugar-sweetened Beverages and Fruit Juice This is one category where the USDA’s guidelines are still found lacking. The AHEI-2010 recommends zero servings of sugar-sweetened beverages and fruit juice. As you cut out sugary beverages, remember that flavored coffee drinks and many mixed cocktails contain a ton of sugar!
Red Meat The other glaring distinction between the current versions of the AHEI and the HEI is consumption of red meat. The AHEI says it’s healthiest to cut out red meat altogether, and that as little as one and a half servings per day could put you in the highest risk category.
Sodium Despite perpetual headlines in the media about how sodium isn’t as bad as once thought, the Harvard team found that not to be the case. While no specific intake levels are listed on their criteria guideline, their findings suggest that sodium intake has a linear correlation with risk — those who consume the least decrease their health risk the most, while those who consume the most are at greatest risk.
Alcohol Alcohol is a hot-button issue when it comes to health studies. Again, the media often help fan the fire of controversy here. While numerous studies have found evidence that light to moderate alcohol consumption reduces cardiovascular risk and overall mortality rates, typical consumption levels for many Americans are well outside of that range.
Specifically, optimal consumption for women is 0.5 – 1.5 ounces of alcohol per day, and for men that upper limit gets pushed to 2 ounces. That means after one 12-ounce beer, a 5-ounce glass of wine or a 2-ounce shot of spirits, you’re cut off.
It’s also important to note that any consumption of alcohol may be associated with greater risk for developing certain types of cancer. So it’s a good idea to talk with your doctor about whether it’s safe for you to consume alcoholic beverages.
Although the AHEI-2010 isn’t a snazzy, neatly wrapped diet, it does give us a great blueprint for how we can minimize health risks by increasing consumption of high-quality foods while decreasing our intake of low-quality foods.