AS the argument goes, diets rich in plant-based foods with minimal animal-based foods are not only best for health but also are necessary to lower greenhouse gas emissions and meet certain climate targets.

Is that really the case, though, or is the opposite, in fact, true? What happens when people eat more plant-based foods in lieu of animal-based foods without meaningful behavior changes to their current eating styles?

Dr. Christopher Cifelli, Jenny Houchins and Elieke Demmer of the National Dairy Council, along with Vitor Fulgoni III of Nutrition Impact, evaluated just that question. They did so by modeling three different dietary scenarios in order to assess the effects on macronutrient intake and nutrient adequacy that resulted from increasing the consumption of plant-based foods or dairy foods.

For their work, they used data from the "National Health & Nutrition Examination Survey 2007-2010" for people two years of age and older (n = 17,387).

The data modeled three different eating scenarios that increased the consumption of: (1) plant-based foods as currently consumed, (2) protein-rich plant-based foods such as legumes, nuts, seeds and soy and (3) milk, cheese and yogurt.

The first two scenarios had equal reductions in animal-based foods consumed to mimic what some in the health industry have suggested to improve health and the environment.

The results showed that increasing the intake of certain foods (and, for the plant-based food model, proportionately decreasing the intake of animal-based foods) within current consumption patterns directly affected nutrient adequacy.

Compared to current consumption, increasing plant-based food intake resulted in improved consumption of key nutrients like iron, vitamin E and folate but also resulted in an increased number of individuals not meeting the estimated average requirement for vitamin A and two nutrients specified in the 2015 Dietary Guidelines for Americans as nutrients of public health concern — those being calcium and vitamin D.

Interestingly, the researchers found that doubling the consumption of high-protein plant-based foods had little effect on nutrient adequacy. They said this was mainly due to the current low consumption of these foods in the U.S., suggesting that a substantial behavior change would be needed to get people to eat more legumes, soy and other protein-rich plant-based foods to help meet their nutrient needs in the absence of animal-based foods.

Finally, compared to current consumption, increasing dairy food intake increased the consumption of energy, saturated fats and sodium but also improved the mean consumption of vitamin A, vitamin D, magnesium and calcium in both children and adults.

As for which eating style is both healthy and good for the environment, the researchers said that is difficult to answer and will take more research. Nutrition and environmental science, they explained, are two complex disciplines and cannot really be separated, but this study did provide additional clues, especially when health is top of mind.

The nutrition gap can be closed with well-balanced, healthy eating styles that contain a mix of dairy foods and healthy plant-based foods, the researchers concluded.

Volume:88 Issue:08