‘Diet stacking’ – following multiple diet strategies at the same time – can lead to potentially serious health risks, new Swinburne research has found.

At this time of year, many people resolve to take control of their health by adopting dietary strategies to lose weight, feel better or improve gut health.

But in this search for relief and rapid results, senior author and Swinburne dietetics expert Dr Caroline Tuck worked with Monash University’s Sarah Melton to discover a growing trend emerging: diet stacking.

“In some cases, the use of multiple diets is necessary and evidence based. But in other cases, people may accumulate diet strategies by layering them with additional restrictions such as gluten-free, low-fat, or ‘clean eating’ without considering whether they’re right for them or discontinuing diets that are ineffective.

“This can potentially worsen symptoms, reduce diet quality, precipitate disordered eating and result in feeling physically and mentally drained.

“Over the long term this could lead to chronic diseases like heart disease, type 2 diabetes, certain cancers, obesity, weakened immunity, poor mental health, osteoporosis and fatigue.”

Dr Tuck says diet stacking should only be used for managing legitimate medical, social or religious needs, and in tandem with health providers.

“We know that individually, many diets have merit. But stacking them can amplify risks such as nutritional inadequacies.

“For example, if someone is vegetarian and planning to start a low FODMAP (fermentable carbohydrate) diet to manage gut symptoms, they’ll find that many vegetarian protein sources are high in FODMAPs. So, when combining these two diets, protein intake requires careful planning.”

Dr Tuck says while it is great that more people are becoming interested in their health and food intake, unnecessary dietary restriction is not encouraged.

“Given the rise in use of diet as therapy, combined with diet culture messaging on social media, diet stacking is increasing. Proper education and guidance with an Accredited Practising Dietitian ensures that diet strategies are used in a safe and effective way.”