Do they work? The latest fad diets and how they stack up

These days it’s hard to watch TV, open a magazine or scroll through social media without reading about the latest fad diet.

These so-called ‘miracle’ diets typically promise a fast way to lose weight and other health benefits, but the science behind it is often little to none. That’s why Starts at 60 spoke to leading nutritionist Teresa Mitchell-Paterson to find out whether they’re worth the hype.

Atkins diet

The high-protein, high-fat and low-carb diet is based on the theory that eating carbohydrates stimulates the production of insulin, which in turn leads to hunger, eating and weight gain. So the Atkins eating plan focuses on cutting out carbs to help the body burn fat instead. The diet allows meat, eggs and some dairy products, and avoids sugar, bread and pasta.

While it focuses on a diet with reduced levels of refined carbohydrates and sugars, because it excludes most fruits, vegetables and grains, Mitchell-Paterson warns you could be missing out on some key nutrients, such as beta carotene, vitamin E and B vitamins.

Paleo diet

The paleo diet, commonly referred to as the caveman diet, is hugely popular these days. It’s designed to emulate the eating habits of humans during the Palaeolithic era — promoting poultry, fish, eggs, fruits, vegetables and meat.

The diet encourages followers to remove processed foods containing added salt, sugar and healthy fats from their diet. And while Mitchell-Paterson maintains that Paleo-style eating has many benefits, the fad diet isn’t without its downsides.

She says the diet cuts out valuable food sources, such as wholegrains and legumes, which are considered good sources of protein and fibre, and can help lower cholesterol. It also removes dairy, which is a good source of calcium, vitamins D and K and other nutrients thought to be good for cardiovascular health

Keto diet

Sharing many similarities to the Atkins diet, this eating plan is all about minimising carbs and upping fats. After the first few days, your body enters ketosis, a state where the body uses fat for energy, which leads to rapid weight loss. It’s important to note, however, ketosis may cause some side effects, such as nausea, headache and mental fatigue.

While there is evidence to suggest that the diet may have some cardiovascular benefits and may help to control seizures in people with epilepsy, Mitchell-Paterson warns that the low-carb diet may have some downfalls.

“Only 5 per cent of the diet is comprised of low-carbohydrate vegetables and leafy greens,” Mitchell-Paterson explains. “This may reduce the diversity of probiotics in the gut and lead to constipation.”

Although low-carb vegetables such as cauliflower and leafy greens are considered keto-friendly, many nutrient-rich vegetables and fruits, such as potatoes, corn, peas, tomatoes, limes and some berries, are all off-limits on the plan.

South Beach Diet

Like many other fad diets, the South Beach Diet may have elements which are generally recognised as healthy, but it’s promised benefits are not backed by any supporting evidence, Mitchell-Paterson explains.

“The explanations of the diet are conflicting, hard to follow and not supported by scientific data.”

The controversial diet has three stages and gradually increases carbohydrate consumption as it progresses while simultaneously decreasing the proportions of fat and protein.

5:2 diet

The 5:2 diet, also called the ‘Fast’ diet, involves eating what you want five days a week, and eating next to nothing for the remaining two. The part-time diet that still allows you to indulge while losing weight is currently the most popular intermittent fasting diet, but is it really good for you?

While its promotion of a lowered calorie intake can benefit many people, Mitchell-Paterson says “weight gain can occur if people go back to eating three meals and snacks again due to a sudden surge of calories.”

The diet is also not suitable for people with diabetes and heart disease or those on blood pressure medication, she adds.