Healthier Diets Associated with Improved Physical Fitness, Study Finds

New research published in the European Journal of Preventive Cardiology suggests that middle-aged adults who follow a healthy diet are more likely to have greater physical fitness. The study, conducted by researchers at Beth Israel Deaconess Medical Center in Boston, provides strong evidence supporting the link between better diets and higher fitness levels.

The researchers found that the improvement in fitness observed in participants with healthier diets was comparable to the effect of taking an additional 4,000 steps per day. Cardiorespiratory fitness, which reflects the body’s ability to use oxygen during exercise and is a strong predictor of overall health, was measured using a maximum effort cardiopulmonary exercise test.

The study included 2,380 individuals from the Framingham Heart Study, with an average age of 54 years and 54% women. Participants’ diet quality was assessed using two indices: the Alternative Healthy Eating Index (AHEI) and the Mediterranean-style Diet Score (MDS). These indices evaluated the intake of various food items, with higher scores indicating a better quality diet that emphasized fruits, vegetables, whole grains, nuts, legumes, fish, and healthy fats, while limiting red meat and alcohol.

After controlling for various factors such as age, sex, body mass index, and physical activity levels, the researchers found that higher scores on both the AHEI and MDS were associated with greater peak oxygen consumption (peak VO2), indicating better fitness. Specifically, an increase of 13 points on the AHEI and 4.7 points on the MDS was linked to a 5.2% and 4.5% increase in peak VO2, respectively.

The researchers also explored the potential mechanism underlying the relationship between diet and fitness by analyzing metabolites in blood samples. They found that certain metabolites were associated with both poor diet and fitness, as well as with favorable diet and fitness. These findings suggest that healthy eating may improve metabolic health, contributing to better fitness and exercise capacity.

It is important to note that this study was observational, and therefore, causality cannot be determined. Additionally, the researchers acknowledged the possibility of a reverse relationship, where individuals who are already fit may be more likely to choose healthier diets.

Nevertheless, the study highlights the numerous health benefits of consuming a high-quality diet, with physical fitness being an additional advantage. The researchers recommend adopting a Mediterranean-style diet, which consists of fresh, whole foods, minimal processed foods, red meat, and alcohol, as a good starting point for improving diet quality.

Further research is needed to better understand the relationship between diet and fitness and to explore potential interventions for promoting healthier lifestyles and improved physical fitness.