Maintaining a healthy body type in middle age isn’t just about looking fit—it plays a crucial role in long-term brain health. Recent research has found that waist-to-hip ratio and diet quality in midlife significantly affect cognitive function as people age.

With obesity rates rising globally, the findings highlight the importance of managing body composition early in life to reduce the risk of dementia and other cognitive impairments. A study tracking participants over 30 years revealed that those with a lower waist-to-hip ratio in midlife had better brain function later on.

The Link Between Body Type and Cognitive Function

Researchers analyzed data from the Whitehall II Study, which monitored over 10,000 participants for three decades. The study focused on 664 middle-aged individuals, tracking their waist and hip measurements over 21 years. Additionally, 512 participants completed detailed diet questionnaires evaluating their intake of fruits, vegetables, whole grains, fats, and sugary drinks.

Freepik | Data shows that lower waist-to-hip ratios in older adults resulted in better working memory.

The results showed a clear pattern- those who maintained a healthier body type, particularly a lower waist-to-hip ratio, exhibited stronger working memory, better executive function, and overall improved cognitive performance in their 70s.

Diet Quality and Its Role in Brain Health

It’s not just body composition that matters—diet quality plays a crucial role in brain function. Participants who followed a nutrient-rich diet in midlife displayed enhanced cognitive abilities, particularly in brain regions responsible for learning, memory, and communication between different areas of the brain.

Even for those who didn’t follow a healthy diet early on, researchers found that adopting better eating habits later in life still led to noticeable improvements in brain health. As one of the study’s authors, Dr. Daria E. A. Jensen, stated, “It’s never too late to take steps toward better brain health, but the earlier you start, the better the outcomes.”

How Obesity Contributes to Cognitive Decline

The growing obesity epidemic has been linked to numerous health risks, including type 2 diabetes, cardiovascular disease, and high blood pressure. However, one of its most concerning effects is its role as a major modifiable risk factor for dementia.

Currently, over six million Americans are living with dementia, and without intervention, this number is projected to double by 2060. These statistics underline the urgency of preventing cognitive decline through lifestyle changes such as weight management, healthy eating, and regular physical activity.

Key Takeaways for Protecting Brain Health

Freepik | To diminish cognitive decline risk, midlife individuals should prioritize a diet rich in fruits and vegetables.

Maintaining a healthy body type in midlife is one of the most effective strategies for reducing the risk of cognitive decline. Here’s what research suggests for better brain health:

1. Monitor Waist-to-Hip Ratio - Keeping a lower ratio is linked to better cognitive performance in later years.
2. Follow a Balanced Diet - Incorporate fruits, vegetables, whole grains, and healthy fats while avoiding excess sugar and processed foods.
3. Stay Active - Regular exercise supports both physical and cognitive health.
4. Make Lifestyle Changes Early - While it’s never too late to improve diet and exercise habits, starting in midlife yields the best results.

Public Health Implications

Experts emphasize the need to integrate dietary and weight management strategies into public health policies to address the rising rates of cognitive impairment. As a neurologist, Dr. Sharmili Edwin Thanarajah pointed out, “Public health measures should prioritize nutrition as a fundamental aspect of brain health, alongside managing metabolic and cardiovascular risks.”

While genetic factors play a role in cognitive health, lifestyle choices remain one of the most powerful tools for preserving brain function. The findings stress the importance of making informed decisions about diet and weight management, especially during midlife, to support better cognitive outcomes in later years.