The basics of a healthy diet are pretty simple

Different healthy diets can yield different results

We Americans would enjoy better health and well-being if we ate better. Alas, few of our compatriots eat a healthy diet. Why not? One possible reason might be the perceived difficulty of determining the healthfulness of foods, even after reading food labels. Or perhaps we’re confused by conflicting claims and inconsistent research findings.

At a basic level, you can greatly upgrade your diet by emphasizing and de-emphasizing certain groups of foods. You’ve doubtless heard many times to eat more fruits, vegetables, whole grains, beans, and nuts. Plus, you’ve heard many times to cut back on white flour (most breads, cookies), sugar-laden foods (sodas, candy), and ultra-processed foods (heat-and-eat dinners, snack foods). If you actually embrace these simple guidelines in your daily eating, you’ll probably end up eating a “healthy” diet.

The US Department of Agriculture develops the Dietary Guidelines for Americans and revises them every five years. The dietary guidelines for 2020-2025 provide the latest science-based dietary advice that supports good health. Researchers have developed diet scores based on the Dietary Guidelines for Americans and on other guidelines. The Healthy Eating Index (HEI) quantified the 1995 Guidelines. The Alternative Healthy Eating Index-2010 (AHEI-2010) includes additional measures of diet quality.

Researchers at Harvard compared the ability of both indices to predict risk of major chronic diseases using data from 71,495 women in the Nurses’ health Study and 41,029 men in the Health Professionals Follow-up Study.  Food intake data were used to create numerical adherence scales for both diets. For both the HEI and the AHEI-2010, higher adherence predicted significantly lower risks of major chronic disease, cardiovascular disease, coronary heart disease, stroke, diabetes, and cancer for women and men. Higher adherence to the AHEI-2010 predicted lower risk of major chronic disease, coronary heart disease and diabetes than the HEI. If you emphasize higher intakes of whole grains, polyunsaturated fats, nuts, and fish, and limits intake of red and processed meats, refined grains, and sugar-sweetened drinks, your healthy diet can reduce you risk of major chronic diseases.

A particular dietary pattern developed for Americans in may not optimally support specific aspects of health and well-being in other regions. Researchers in Sweden developed the Nordic Prudent Diet (NPD), which reflects food preferences and availability in Scandinavia. The NPD was designed to reduce risk of cognitive decline in older adults. A follow-up study compared NPD with four other diets developed in other regions or for different purposes. These diets included the 1) DASH diet (designed to prevent hypertension), 2) MIND diet (a hybrid of the DASH and Mediterranean diets), 3) Mediterranean diet, and 4) Baltic Sea diet. The four diets differed somewhat in the foods that were emphasized or de-emphasized. Data for the study came from 2,223 participants with an average of 70 years in the Swedish National Study on Aging. Moderate or high adherence to NPD predicted less cognitive decline than the other four diets over six years of follow-up. High adherence to NPD predicted a significant 82 percent lower risk of cognitive decline than the other diets. Finally, NPD scores more accurately classified participants as having cognitive decline or not. Thus, a healthy diet developed in a particular region to promote a specific outcome may lead to better results compared to other diets.

A particular healthy dietary pattern might not be optimal for every health and wellness outcome. For example, the AHEI-2010 mentioned predicted lower risk of major chronic disease, coronary heart disease and diabetes. But that about other outcomes, such as frailty? It refers to aging-related diminution in bodily systems resulting in compromised strength and energy. Diet greatly affects the development of frailty.

Canadian researchers investigated the links between frailty, five healthy dietary indices, and mortality. The indices included the Nutrition Index (NI), energy-density Dietary Inflammatory Index (E-DII™), Healthy Eating Index-2015 (HEI-2015), Mediterranean Diet Score (MDS), and Dietary Approaches to Stop Hypertension (DASH) with frailty and mortality. The NI counts deficits of 18 nutrients. The E-DII™ included 30 dietary factors associated with risk of inflammation. The HEI-2015 reflected the 2015 Dietary Guidelines for Americans and emphasizes fruits, vegetables, beans dairy, high-protein foods, seafood, plant proteins and de-emphasizes refined grains, sodium, added sugar, and saturated fats. The MDS emphasizes non-refined cereals, legumes, fruits, nuts, vegetables, fish, and mono-unsaturated fatty acids, and de-emphasizes red meat, processed meat, poultry, dairy, and high alcohol intake. The DASH diet seeks to reduce risk of hypertension by emphasizing fruits, vegetables, low-fat dairy.

Data came from 15,249 adult participants in the 2007-2012 waves of the US National Health and Nutrition Examination Survey. All of the diets significantly predicted reduced risk of frailty. In addition, after adjusting for confounding factors and frailty, all of the diets significantly predicted lower 8-year mortality risk. Thus, a healthy diet will likely reduce your risk of frailty and help you live longer, whether or not you’re frail.

Researchers at Tufts University developed and validated a nutrient profiling system, the Food Compass, using a broad range of food attributes and consistent scoring. Food Compass scores 54 attributes across nine health-relevant domains: nutrient ratios, vitamins, minerals, food ingredients, additives, processing, fats, fiber and protein, and phytochemicals. The summed domain scores yields a Food Compass Score (FCS) ranging from 1 (least healthy) to 100 (most healthy) for all foods and beverages. The FCS distinguished foods and categories of foods. For example, savory snacks and sweet deserts had an average FCS of 16, while legumes (beans, lentils) had an average score of 79. Examples of foods with scores of 90 or above include vegetable curry, seafood garden salad, plain nonfat Greek yogurt, salmon, a dozen fruits, many vegetables, Cheerios, tomato juice, and celery juice. The FCS also distinguishes between certain foods and beverages better than other nutrient profiling approaches, such as NOVA, Health Star Rating, and Nutri-Score. You can find Food Compass Scores for numerous foods at https://sites.tufts.edu/foodcompass/our-data/.

You can use the results of these studies to find foods that you enjoy and which support better health. Get started now to eat a healthy diet!