JW: The last time I received nutritional education was decades ago when a giraffe called Healthy Harold taught me about the food pyramid. What has been the biggest development in nutritional science since then?
AS: Well, Harold certainly made his mark on many but we have learnt so much about how food affects us in the last decade. We used to think that the food we eat was just important for our growth and physical functioning but we now understand it also affects our mental health. This is a fascinating new area of science called nutritional psychiatry.
JW: It seems strange to think that our guts can have such an impact on our brain. What is the research now telling us about the role nutrition can play in mental health?
AS: There is now a very consistent and compelling evidence-base from all around the world and right across the lifespan showing us that what we eat matters to our mental health. We know diets higher in fibre rich plant foods and healthy fats are consistently associated with a reduced risk of depression, while diets low in fibre and high in highly processed sugary and fatty foods are consistently associated with an increased risk of depression. There are many different mechanisms by which we think food affects our mental health including the balance and diversity of our gut bacteria, inflammation and the growth on new neurons in the hippocampus – this is this part of our brain which is important for mood, memory, learning and mental health and it can grow and shrink depending on the quality of our diet.
JW: Just about every product we purchase seems to carry some nutritional claim. For those who are a bit bamboozled by it all, are there some simple rules of thumb that can help us to make healthy choices?
AS: A really good rule is that the more health claims there are, the more likely it is not to be a healthy choice. For example, products that claim to have “no added sugar” probably contain sugar alternatives which have been seen to have a negative impact on the gut microbiome. So many products state they are high in protein, which we all seem to be drawn to, but most of us eat twice as much protein as we need and things like protein bars are the perfect example of a highly processed food. They are full of ingredients that we don’t recognise. Whenever you choose a product, look at the ingredient list. If it contains things that you wouldn’t find in your own cupboard, there’s probably a better choice for you, especially if it’s something you eat regularly.
JW: Attempts to bully and shame people into eating healthy tend to be quite unwelcome and highly ineffective. You take a far more empowering approach.What is the key to building a healthy relationship with food?
AS: We think it comes down to loving what you eat. If you love the way you eat, then you will continue to do it. There isn’t one way to do this, and no food is off limits. We encourage people to take the time to consider what they like about food and think about how it makes them feel. When you have more energy and you feel good about your food choices you are more likely to take some time to put together simple meals and snacks that you enjoy. While we see in the research that obesity is associated with an increased risk of depression, we also see that improving diet quality is the key to improving mental health, not weight loss. We think this is a really empowering message because it takes the pressure off people to lose weight and means we can focus on making our food delicious by adding things like extra virgin olive oil and avocado to salads and snacking on nuts and dark chocolate.
JW: Lately, my supermarket bill has become a lot larger. Is it possible to eat well on a budget?
AS: Yes! There have been detailed cost analysis done comparing the cost of the average Australian diet to a healthy eating pattern like a Modi Med diet and this shows an average cost saving of $238/year. Here are some tips to help: frozen and tinned vegetables are just as nutritious as fresh varieties, tinned lentils and fish are highly nutritious and only cost a couple of dollars. When it comes to fresh fruit and veg, look for what’s in season it tends to be the best quality and the best price. Extra virgin Olive oil has gone up in price recently so I try to buy it in bulk when it’s on special. Wholegrains are also really important and these are cheap and great for adding to soups and stews along with lentils and legumes, tins of tomato and any leftover veg you have. This also helps to reduce wastage.
JW: Really busy days are often when we could most benefit from something nutritious. Do you have a go-to for those times when you want something tasty, filling and super-simple to prepare?
AS: I always have a soup in the freezer – it’s a simple, norishing go-to. If I can’t have that I may throw together a bag of salad with felafel, hummus and pita bread or a tin of tuna, with lentils and salad. If I’m working from home, roasted cherry tomatoes on sourdough with avocado and rocket is my all-time favourite.