Dietary diversity and health benefits
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Dietary Diversity and All-Cause Mortality
Research consistently shows that greater dietary diversity is linked to a lower risk of all-cause mortality. A meta-analysis of longitudinal studies found that people with higher total dietary diversity had a 22% lower risk of dying from any cause, and this benefit was also seen for deaths related to cancer and cardiovascular disease in certain groups . These findings suggest that eating a wide range of foods, especially healthy ones, can help people live longer .
Dietary Diversity and Metabolic Health
Several studies highlight the protective effects of dietary diversity against metabolic diseases. Greater diversity across major food groups, and within fruits and vegetables, is associated with a reduced risk of type 2 diabetes and cognitive decline . However, the benefits depend on the types of foods included; diversity that includes unhealthy foods may increase the risk of obesity, while diversity focused on healthy foods is linked to better mental health and lower risk of depression .
Dietary Diversity, Diet Quality, and Obesity
Dietary diversity is generally associated with better diet quality, including higher intake of fiber, fruits, and vegetables, and lower consumption of ultra-processed foods . However, the relationship with obesity is complex. Some evidence suggests that greater dietary diversity, especially when it includes processed and unhealthy foods, may be linked to weight gain and obesity in adults . In contrast, higher dietary diversity is associated with lower overweight and obesity rates in adults, but not consistently in children and adolescents . This suggests that the healthiness of the foods chosen is crucial when considering the benefits of dietary diversity 34.
Dietary Diversity and Healthy Aging
Multiple studies show that higher dietary diversity is associated with healthier aging. Older adults with more diverse diets have better physical function, lower risk of cognitive decline, and improved psychological well-being 5678. These benefits are especially strong in the younger elderly, and dietary diversity appears to slow biological aging, possibly by reducing oxidative stress 5678. Consuming a variety of foods from different groups, such as meat, poultry, aquatic products, and fruits, is linked to better aging outcomes 5678.
Dietary Diversity and Cognitive Health
A diverse diet is also important for maintaining cognitive function in older adults. Studies consistently report that higher dietary diversity is linked to better memory, lower risk of cognitive decline, and reduced risk of dementia and Alzheimer’s disease 2679. This suggests that promoting dietary diversity could be a promising strategy for protecting brain health as people age 2679.
Dietary Diversity and Nutrient Adequacy
Dietary diversity is a key indicator of adequate energy and nutrient intake, especially in populations at risk of micronutrient deficiencies . Assessing the variety of food groups consumed is a common way to measure dietary diversity and is useful for evaluating the impact of nutrition programs .
Conclusion
Overall, the evidence shows that dietary diversity—especially when focused on healthy foods—offers significant health benefits, including lower mortality, reduced risk of metabolic diseases, better diet quality, healthier aging, and improved cognitive function. However, the benefits depend on the quality of foods chosen, highlighting the importance of promoting variety within healthy food groups for optimal health outcomes.
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