Weight Management, Diet, and Nutrition

Being overweight, diet, and nutrition can all have an impact on brain function and health.

⏱ 3 min read

Weight management

Being overweight can directly impact your physical mobility and is linked to several medical complications, many of which can have an adverse effect on our brain health, such as diabetes or high blood pressure. Body Mass Index (or BMI) and waist circumference are the measurements used to determine if a person is overweight or obese.

People who are obese in midlife have an increased risk of dementia compared to those with healthy body weight. Obesity is also linked to type 2 diabetes, cancer, and cardiovascular disease. Some evidence suggests that interventions aimed at weight loss could improve cognitive functions like attention, memory, and language.

If you are overweight and don’t know where to start, ask your doctor about consulting a dietitian to work out a plan that is best for you. Managing your nutrition and following the physical activity guidelines will help you to manage your weight in the long run. A balanced diet is not only important for weight management but is also an important factor for overall brain health.

Diet and nutrition

What we eat can have a profound effect on our brain function. Aside from eating a well-balanced diet, certain diets – in particular, the Mediterranean Diet – have been associated with many health benefits, such as a decreased risk of heart disease, cancer, Alzheimer disease, and Parkinson disease. In some studies of people at risk for dementia, people who ate a Mediterranean diet improved their brain function by a moderate amount.

The Mediterranean Diet

The Mediterranean Diet is exactly what it sounds like; common types of food that are consumed in many Mediterranean countries like Greece and Italy. The Mediterranean Diet consists of the following:

  • Eating mostly plant-based foods, such as fruits and vegetables, whole grains, legumes and nuts
  • Replacing butter with healthy fats such as olive oil and canola oil
  • Using herbs and spices instead of salt to flavour foods
  • Eating fish and poultry at least twice a week
  • Limiting red meat to no more than a few times a month
  • And, optionally drinking red wine in moderation

DASH and MIND Diets

A low-salt diet called Dietary Approaches to Stop Hypertension (DASH) has also been shown to deliver significant health benefits. Studies testing the DASH diet found that it lowers blood pressure, helps people lose weight, and reduces the risk of type 2 diabetes and heart disease.

Yet another eating pattern that may support healthy aging is the MIND diet, which combines a Mediterranean-style eating pattern with DASH. It’s essentially the Mediterranean Diet with the addition of other foods that are high in antioxidant properties such as berries. Researchers have found that people who closely follow the MIND diet have better overall cognition — the ability to clearly think, learn, and remember — compared to those with other eating styles.

Learn more about the Dietary Approaches to Stop Hypertension (DASH) eating plan.

Brain Health Food Guide

The Brain Health Food Guide is an evidence-based approach to healthy eating for the aging brain developed by Dr. Matthew Parrott in collaboration with members of the Canadian Consortium on Neurodegeneration in Aging (CCNA). It contains some excellent healthy diet recommendations aligned with the Mediterranean diet in a practical 2-page brochure.

Download the Brain Health Food Guide.

Vitamins, supplements and antioxidants

Vitamins – Unless tests show you genuinely lack specific vitamins (for example, a true Vitamin B12 deficiency), supplementing doesn’t help. Recent research has found an association between vitamin D supplementation and reduced risk of developing dementia, but more research is required in this area before recommending supplementation for dementia prevention. Studies have been done showing no benefit for supplementation with vitamin E, vitamin B12, selenium, ginkgo, ginseng, multivitamins and many others.

Coconut oil – There was some thought that by changing the brain’s fuel source (from sugars to fats), that we could somehow improve brain function. The idea behind consuming coconut oil is precisely that. Unfortunately, at this time, there’s not sufficient scientific evidence to support this idea, and we therefore can’t recommend the consumption of coconut oil for brain health.

Key points from this topic

  • Maintain a healthy weight.
  • Reducing obesity can help with a number of conditions in addition to helping to promote brain health.
  • Diet changes can have a powerful effect on brain health (and other health benefits).
  • check out the Mediterranean diet or the Brain Health Food Guide.
  • Don’t waste your money on unnecessary vitamins or supplements unless your doctor has identified an actual vitamin deficiency or recommended supplementation for some other health reason (e.g., vitamin D or calcium for your bone health).
  • As with many lifestyle changes, start with small changes that seem manageable so you can maintain them in the long run.


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What other people are saying:

"This study has been a real eye-opener, as it has educated and informed me on concepts I previously did not associate with the risk of developing dementia." - Study participant, 25-34 years old.

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"This is a very timely topic as I look around and see friends and relatives coping with the effects of dementia." - Study participant, 65-74 years old.

"Each topic was well focussed. The medical terminology was easy to understand and very informative." - Study participant, 65-74 years old.

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Anthony Levinson

Anthony J. Levinson, MD, MSc, FRCPC

Neuropsychiatrist, Professor; Faculty of Health Sciences, McMaster University

About this Project

Who authored and edited this page?

This page was developed by the Division of e-Learning Innovation team and Dr. Anthony J. Levinson, MD, FRCPC (Psychiatry). Dr. Levinson is a psychiatrist and professor in the Department of Psychiatry and Behaviour Neurosciences, Faculty of Health Sciences, McMaster University. He is the Director of the Division of e-Learning Innovation, as well as the John Evans Chair in Health Sciences Educational Research at McMaster. He practices Consultation-Liaison Psychiatry, with a special focus on dementia and neuropsychiatry. He is also the co-developer of the iGeriCare.ca dementia care partner resource, and one of the co-leads for the McMaster Optimal Aging Portal. He and his team are passionate about developing high-quality digital content to improve people's understanding about health. By the way, no computer-generated content was used on this page. Specifically, a real human (me) wrote and edited this page without the help of generative AI like ChatGPT or Bing's new AI or otherwise.

Are there any important disclosures or conflicts of interest?

Dr. Levinson receives funding from McMaster University as part of his research chair. He has also received several grants for his work from not-for-profit granting agencies. He has no conflicts of interest with respect to the pharmaceutical industry; and there were no funds from industry used in the development of this website.

When was it last reviewed?

August 22, 2023

What references and evidence were used to create this content?

Content was written and adapted based on credible, high-quality, non-biased sources such as MedlinePlus, the National Institutes for Mental Health, the McMaster Optimal Aging Portal, the American Psychiatric Association, the Cochrane Library, the Centre for Addictions and Mental Health (CAMH) and others. In particular, evidence-based content about dementia risk reduction was also derived from the World Health Organization and the Lancet Commission reports. Please see additional references on the e-learning lesson landing page

Who funded it?

The initial development of some of this content was funded by the Centre for Aging and Brain Health Innovation, powered by Baycrest. Subsequent funding was through support from the McMaster Optimal Aging Portal, with support from the Labarge Optimal Aging Initiative, the Faculty of Health Sciences, and the McMaster Institute for Research on Aging (MIRA) at McMaster University, and the Public Health Agency of Canada. There are no conflicts of interest to declare. There was no industry funding for this content.