DIET QUALITY AND HEALTH
Dietary quality is an important determinant of weight gain and obesity, and a vast body of evidence shows that diet quality directly affects the risk of almost all important diseases independent of its effect on body weight. A previous report from the Centers for Disease Control and Prevention (CDC) indicated some reduction in obesity among young children, but the most recent data suggest that this was a statistical aberration, and the trends in obesity among adolescents and adults have continued upwards.
A recent projection based on historical weight trajectories predicted that 57 percent of today’s children will be obese by age 35. The health implications of weight gain among adults, which accounts for about half of the excess obesity in the U.S., were detailed in a recent report. The amount of weight gained by adults up to age 55 strongly predicted poorer health after age 55, including rates of cardiovascular disease, type 2 diabetes, various cancers, reduced quality of life, and overall mortality after age 55.
These findings highlight the need to redouble our efforts to control weight gain among both children and adults, and that failure to do so will have serious personal and societal consequences. That noted, large differences in obesity rates within the U.S. and across countries indicate that this epidemic is not inevitable.
The quality of foods and beverages in our diets plays a major role in the cause, and potentially the prevention, of excess obesity. Dietary quality has been slowly and steadily improving in the U.S., especially in reduction in consumption of trans fat and sugar-sweetened beverages, but our score for overall dietary quality is only close to 50 on a scale of 100. This and the failure to control the obesity epidemic highlight the urgency of improving dietary quality for everyone in every venue possible.
DEFINING DIET QUALITY
The indicators of diet quality the Menus of Change initiative has used for tracking trends have been selected because they reproducibly predict risks of major diseases in multiple, large prospective studies. These indicators are discussed in more detail and with additional references on the Harvard T.H. Chan School of Public Health website, Nutrition Source. They are intakes of:
- Vegetables (not including potatoes)
- Whole Fruits
- Whole Grains (especially more intact, or cut, versus ground whole grains, to replace refined grains)
- Nuts and Legumes, including soy-based foods
- Plant Oils (liquid, rich in polyunsaturated and monounsaturated fats, from non-tropical, non-hydrogenated sources)
In practice, increasing polyunsaturated fat means using liquid plant oils (i.e., liquid at room temperature) instead of butter, lard, partially hydrogenated fats, or tropical oils (e.g., palm, palm kernel, and coconut oils) wherever possible. These plant oils also contain healthful monounsaturated fats. Because of widespread promotion of coconut oil as a health-promoting fat, the American Heart Association recently released a review of available evidence. This review emphasized the lack of evidence on long-term health consequences, but clear evidence that coconut oil has adverse effects on blood cholesterol fractions when compared with liquid plant oils. Moderate use of coconut oil when the special flavor is important is reasonable, but is best not used as a basic cooking fat.
- Trans Fats (to be eliminated)
- Red and Processed Meat (to be substantially reduced)
- Sugar-sweetened Beverages (to be substantially reduced)
- Sodium (salt added in processing and cooking, to be substantially reduced)
Sodium reduction deserves special attention because it is the only indicator of diet quality that has been moving in the wrong direction. Unprocessed foods contain very little sodium, and foodservice operators (along with food manufacturers) play a major role in determining the amount of sodium consumed by the public.
Our indicators of diet quality do not include dairy foods as they are not essential and are not clearly related to risk of major health outcomes, including fractures. Consumption of cheese has been increasing dramatically over the last several decades in the U.S., becoming almost routine in salads and sandwiches. Cheese provides large amounts of sodium along with less healthy fats and many calories. Consuming smaller amounts of cheese and the use of alternative ways to add flavor and variety to these foods, such as using nuts, are desirable.
Overall, evidence accumulated over the last several decades strongly supports plant-forward food choices, meaning a style of cooking and eating that emphasizes and celebrates, but is not limited to, plant-based foods—including fruits and vegetables (produce); whole grains; beans, legumes (pulses), and soy foods; nuts and seeds; plant oils; and herbs and spices—and that reflects evidence-based principles of health and sustainability. This pattern was examined directly in a recent analysis using a plant-based dietary index that gives one point for each serving of healthy plant-based foods, and a negative point for each serving of animal-sourced foods. Among over 200,000 men and women followed for up to 26 years, a higher plant-based score was linearly related to lower risk of coronary heart disease. This finding is consistent with an earlier report that found that a higher plant-based score was also related to lower risk of type 2 diabetes.
In the past year, the plant-forward dining trend has become part of the restaurant industry mainstream, both a focus of culinary innovation and also now a feature of more and more menus. Large chains like Sonic Drive-In have even added a blended meat-mushroom burger to their core offerings while some of the fastest-growing restaurant chains are built around plant-forward menus, in both global and traditional U.S. concepts. A recent analysis by Changing Tastes also found that the increase in spending on meals prepared by the restaurant industry is strongly correlated with our decline in beef consumption.
This recent leadership from the culinary profession and restaurants of all sizes comes at a crucial time, as efforts to promote healthier diets have weakened at the federal level, putting the responsibility for offering healthy choices squarely in the hands of the foodservice industry. It’s important not to overlook the role of foodservice in also offering options for children that are higher in diet quality and supportive of their health; providing these better choices can be a win-win for both restaurants and for kids. While progress has been made, the supply of healthier kids’ meals needs to grow alongside consumer demand. Work at ChildObesity180 has shown that this is possible. Kids and their parents have positive attitudes toward healthier kids’ meals, and when put to the test these attitudes can translate into action. “You’re the Mom”, a campaign to boost demand for healthier kids’ meals among frequent quickservice restaurant customers, has shown potential to shift ordering patterns toward healthier offerings.
In foodservice operations, chefs can most effectively improve the diet quality of their customers by adopting healthier practices themselves. Beyond adding craveable plantforward dishes to their menu, this means reducing the amount of red meat they serve, relying on herbs and spices rather than solely on salt for flavor, or cooking with healthier fats. Those strategies can be as explicit or implicit as they’d like, depending on their clientele, but must be part of their menu design.
While public policy and nutrition promotion efforts have stalled, leading restaurant companies are making significant moves to reduce beef consumption, offer innovative and healthier sides, spark new customer and media interest in plant-forward flavors, and introduce new beverage choices.
- Diet quality in the U.S. remains low and is helping to fuel an unrelenting epidemic of obesity.
- In general, healthy plant-forward diets will provide improved health and well-being.
- While public policy and nutrition promotion efforts have stalled, leading restaurant companies are making significant moves to reduce beef consumption, offer innovative and healthier sides, drive interest in plant-forward flavors, and introduce new beverage choices.