Healthy diet or food fad?

If you’re confused about the health benefits of the latest popular diets here’s what you need to know.

Fit&Well magazine
June 2015

Every few months there’s a buzz about a new eating plan. But how do you separate hype from healthy eating habits? We’ve assessed three diets that have been getting plenty of press.

The Paleo diet

Said to be based on what our Palaeolithic ancestors ate, this diet involves eating mostly protein, fat, nuts and non-starchy vegetables, as well as cutting out dairy, grains and sugar.

The Paleo diet encourages you to give up processed foods, which reduces your intake of fats, sugar, salt and junk food in general.

“Most people eat more protein on this diet, which can help you feel full for longer, so it may aid short-term weight loss,” says Melanie McGrice, accredited practising dietician and board member of the Australian Dieticians Association.

“However,” she warns, “the rapid weight loss is often due to eating fewer carbs, which helps you burn glycogen stores so you quickly lose fluid. Most people regain this weight when they return to less restricted eating.”

Reducing your grains intake can result in a low-fibre diet, which can cause constipation and has been linked with other health issues such as bowel cancer, heart disease and diabetes.

“The excess protein consumption encouraged on the Paleo diet can cause kidney problems, while the high intake of foods such as bacon and red meat can increase the risk of bowel cancer,” says nutritionist Rosemary Stanton.

Meanwhile the combination of meat and foods such as coconut milk and oil can result in a high intake of saturated fats which, in excess, are linked to heart disease and stroke.

“Paleo man ate wild lean meat only once every few weeks because he didn’t have access to regular meat stores,” says the Heart Foundation’s National Director of Cardiovascular Health Dr Robert Grenfell.

He mostly lived in a half-starved state and died around the age of 25, before he could get heart disease, so we shouldn't be using him as an example of the benefits of a diet high in saturated fats.”

If you are going Paleo, load up your plate with vegies, not meat. “Not just green vegetables but those high in soluble fibre, such as starchy foods like potatoes, sweet potatoes and bananas,” McGrice advises. “Their soluble fibre binds to cholesterol and helps remove it from the body.”

Flexitarian

This diet involves eating vegetarian on one, two or more days a week and having some meat on the other days.

One benefit is that vegetables are fairly inexpensive and available in most restaurants. “A vegetarian diet is also lower in fat and higher in fibre, and this combination helps people feel fuller so kilojoule intake may be less on days of eating vegetables, reducing weight over time,” McGrice says. “An added bonus of meat-free days is that flexitarians easily meet the recommended daily intake of vegetables.”

Stanton is a fan of the flexitarian approach and believes this trend towards plant-based diets is the way of the future. “Many plant foods contain protein, and research shows protein intake by Australian vegetarians easily meets recommended dietary intakes, while most of us eat way more protein than needed,” she explains.

The downside? “Some people find vegetarian meals involve more time chopping and cooking food,” says McGrice. “If your vegetarian dinner consists mostly of toast, pasta or rice with a few token vegies and lots of cheese or other heavy sauces, this is clearly not a balanced diet.”

Try vegetable dishes from different cultures and serve small two-course meals for variety, such as salad and a hearty soup containing beans.

Intermittent fasting

This is often called the 5:2 eating plan. On two days of each week you eat around 2,000 kilojoules (500 calories), consuming foods low in carbohydrates such as meat, fish and eggs. On the other five days you eat as usual.

Many people report a two-day weekly fast is much easier to stick to than a diet as you only have to restrict your calorie intake occasionally.

“Research has shown people following this plan often experience weight loss and improvements in their insulin sensitivity, reducing risk of type 2 diabetes,” McGrice says. “It can also help retrain eating habits so people feel full after eating smaller portions.”

However, intermittent fasting can lead some people to yoyo diet. “It may encourage them to skimp on food on fasting days, then binge on other days instead of eating a nutritious diet on all days of the week,” she says.

“If too little protein is eaten on fasting days your body may break down muscle instead of fat to use as fuel. Over time this could slow your metabolic rate, which is not good for weight maintenance in the long term.”

Consider seeing a dietician for advice on quality meal replacements to use on your fasting days.

Note: Always consult a doctor before embarking on a radically new eating regime.