Eating the equivalent of five servings of fruits and vegetables per day can have the same positive impact on physical fitness as taking 4,000 steps, according to a recent study published in the European Journal of Preventive Cardiology.
The study, conducted by researchers from Harvard's Beth Israel Deaconess Medical Center, provides robust evidence supporting the link between a healthy diet and improved fitness. Lead author Dr. Michael Mi stated, "The improvement in fitness we observed in participants with better diets was similar to the effect of taking 4,000 more steps each day."
To investigate this connection, the researchers assessed the oxygen levels of 2,380 individuals while they ran on a treadmill. All participants engaged in the same amount of physical activity and acknowledged the role of nutrition in their fitness levels. The volunteers also completed a food frequency questionnaire, reporting their consumption of 125 different food items over the past year.
The findings suggest that incorporating a diet rich in fruits and vegetables can have substantial benefits for physical fitness, providing an alternative or complementary approach to increasing physical activity levels.
The researchers evaluated the quality of participants' diets using the Alternative Healthy Eating Index (AHEI) and the Mediterranean-style Diet Score (MDS), both of which are indicators of heart health. Factors such as age, sex, daily energy intake, BMI, smoking, cholesterol levels, blood pressure, diabetes, and regular physical activity were considered in the assessment.
Higher scores on these indices indicated better dietary quality, emphasizing the consumption of vegetables, fruits, whole grains, nuts, legumes, fish, and healthy fats, while limiting the intake of red meat and alcohol.
Dr. Mi highlighted that in middle-aged adults, healthy dietary patterns were strongly associated with improved fitness, even after accounting for habitual activity levels. The relationship between healthy diets and physical fitness was similar among women and men, but more noticeable in individuals below the age of 54.
Furthermore, individuals who closely adhered to the Mediterranean diet exhibited a fitness level comparable to those in the researchers' previous studies who averaged around 4,000 steps per day. These findings underscore the positive correlation between adopting healthy eating patterns and enhancing physical fitness.
The quality of participants' diets was assessed using the Alternative Healthy Eating Index (AHEI) and the Mediterranean-style Diet Score (MDS), both of which are related to heart health. Factors such as age, sex, daily energy intake, BMI, smoking, cholesterol levels, blood pressure, diabetes, and routine physical activity were taken into consideration during the evaluation.
Higher scores on these indices indicated a better quality diet, emphasizing the consumption of vegetables, fruits, whole grains, nuts, legumes, fish, and healthy fats, while limiting the intake of red meat and alcohol.
Dr. Mi stated that in middle-aged adults, adopting healthy dietary patterns was strongly and positively associated with improved fitness, even after accounting for habitual activity levels. This relationship between healthy diets and physical fitness was similar among women and men, but more pronounced in individuals under the age of 54.
Furthermore, individuals who closely adhered to the Mediterranean diet exhibited a fitness level equivalent to those in the researchers' previous studies who averaged about 4,000 steps per day.
The Mediterranean diet, which has been consistently ranked as the best overall diet by US News & World Report, emphasizes the importance of sourcing high-quality ingredients and filling one's plate with nutrient-rich whole foods and grains. It encourages the consumption of fresh produce, lean protein such as fish and chicken, and antioxidant-rich olive oil.
Due to their high fiber content, fruits and vegetables have a natural fat-burning effect that aids metabolism.
The presence of antioxidants in abundance within fruits and vegetables also contributes to preventing inflammation and other health issues.
The analysis also identified 24 metabolites, which are substances produced during food digestion and released into the bloodstream during exercise. These metabolites were found to be associated with either good or poor diet and fitness patterns.
"Our metabolite data suggests that consuming a healthy diet is linked to better metabolic health, which could potentially explain the improved fitness and exercise capacity," stated Dr. Mi. However, it is important to note that this study was observational, so it cannot establish a cause-and-effect relationship between a healthy diet and physical fitness. It also does not rule out the possibility of a reverse relationship, such as fit individuals choosing to eat well.
Dr. Mi emphasized that there are already numerous compelling health reasons to adopt a high-quality diet, and the association with fitness is an additional one. He recommended starting with a Mediterranean-style diet, which emphasizes fresh, whole foods while minimizing processed foods, red meat, and alcohol.
Recent research conducted by the University of Sydney suggests that women who follow the Mediterranean diet have a nearly 25% lower risk of heart disease and premature death.
Furthermore, an earlier study by Harvard University identified the Mediterranean diet as one of the four common healthy eating patterns that can reduce the risk of premature death by up to 20%.