Brain Health Tips: Weight
Research shows that brain health is promoted by maintaining a healthy weight.
A special thanks to this month’s contributors. Carol Wham is a dietitian and professor of public health nutrition at Massey University in Auckland. Joke van Staveren and Jane Hobson are physiotherapists with the Canterbury District Health Board in Christchurch.
Being Underweight
While being underweight has been associated with higher rates of dementia, this is complicated because people with early dementia can often report changes in appetite and diet.
Becoming underweight can be a special problem for people living with dementia because the illness can cause impaired appetite, taste and smell as well as difficulties with planning meals, shopping for food, cooking, and eating. Food energy requirements may also be higher, as dementia can sometimes lead to much increased physical activity, such as restlessness.
When being underweight is a problem, we need to consume more energy from foods and drinks by eating small amounts often, so we build our bodies up more than we burn off through physical activity.
A medical assessment of underlying causes and a dietitian’s advice on ways to increase healthy calorie intake can be helpful. The problem may be simple to solve, such as eating with others, fixing ill-fitting dentures, adjusting a medication that is lowering appetite, arranging pre-prepared meals from family or a service such as “Meals on Wheels”, or providing high-energy snacks and drinks.
A Healthy Weight
On the other hand, overeating and drinking too much alcohol can result from our modern lifestyle with limited opportunities for physical activity. This means maintaining a healthy weight can be challenging. Two-thirds of adults were found to be overweight (35.3%) or obese (30.9%) in the latest New Zealand Health Survey 2019/20.
To check whether you or someone you care about has a healthy weight compared to height, use the Heart Foundation body mass index (BMI) calculator.
How Might High Weight Increase the Risk of Dementia?
A large overview of studies found that being obese (BMI ≥30) was associated with late-life dementia.
As body weight increases, it seems blood flow and activity in the brain decrease, which is associated with developing Alzheimer’s disease.
High BMI can increase your blood pressure and the risk of type 2 diabetes. These factors are both linked to a higher risk of Alzheimer’s disease and vascular dementia.
Losing Weight
Losing even a small amount of weight when we start from an overweight position can improve our quality of life and make us more mobile and energetic.
Avoid fad diets; they don’t work long term. If a diet sounds too good to be true, the chances are it is! Losing weight is not achieved via a ‘quick fix’ solution.
One way we can think about this is to improve our diet step by step, every few months, rather than completely overhaul it in one go. Here’s a guide to following a heart-healthy way of eating in the right amounts from the NZ Heart Foundation.
It’s about consuming less energy from foods and drinks than we burn off through physical activity. The main ways to do this are to choose healthier foods, to eat a bit less of most things (except all those colourful non-starchy vegetables and fruit), and to move more. The best plan is to set realistic goals we can stick to.