2018 diet trend comparison

From alkaline to the Whole30, we look at the pros and cons of the latest weight-loss trends.
Published 12 June 2018

Experts look at the pros and cons of different trending diets

Diet pros and cons

At any one time, more than 2.3 million Australians report being on a diet – and many more are considering a plan to lose weight. But with a global emphasis shifting to a healthy lifestyle, how do we find a weight-loss method that works, is easy to stick to and has the added benefit of being good for our health?

The truth is, many trendy diets are not balanced, healthy or able to achieve long-term benefits, says accredited practicing dietitian Georgia Bevan. “As a society we have become obsessed with weight and appearance, with little concern on the impact of all these fad diets on our health,” Bevan says. “Instead, I get my clients to focus on their ‘why’. Of course this can be appearance-based, but often people have a desire to be healthier.” Bevan says a holistic approach looking at sleep, hydration, exercise and eating better-quality food often garners the best results.

“Small changes each day, week and month build into long-term behaviours. When we improve our lifestyle as a whole, weight loss is usually a secondary positive result,” she says. We look at some popular diets currently available, and speak to experts about the pros and cons.


What is it?

WW is more of a lifestyle, based on a science-backed Points® system where foods provide a certain number of points. Members can choose from Studio, Personal or Digital Coaching. “WW currently has around 3.5 million active members and 32,000 meetings per week globally,” says Nicole Stride, WW dietitian. “With more than 50 years of experience, WW is successful because it takes the latest science on food, mindset and movement and teaches you the skills to build lifelong healthy habits.”

Pros of the WW program

“WW has no food group restrictions, so you’re less likely to become nutrient deficient,” says Olivia Bates, accredited practising dietitian and founder of baby food company Nourishing Bubs. “The program involves education, WW Workshops, and support, and encourages cooking at home and physical activity.” The WW program is backed by scientific research. An international study of 772 overweight people found those whose doctors put them on the WW program lost around twice as much weight as people who received standard weight-loss care over 12 months.

Cons of the WW program

“If you don’t enjoy cooking it might not be ideal,” Bates says. The cost of membership is another factor to consider.

Whole30 diet

What is it?

A clean eating plan that involves avoiding sugar, grains, dairy, legumes, artificial sweeteners, and alcohol for 30 days. You can eat meat, veggies, some fruit, and natural fats.

Pros of the Whole30 diet

“Whole30 encourages the consumption of whole foods, thus helping with the elimination of processed foods,” Bates says. “The program has no measuring or kilojoule counting and encourages reading labels, which is a great habit for life.”

Cons of the Whole30 diet

“By cutting out major food groups – dairy and grains and legumes – adopters are at high risk of several nutrient deficiencies including B vitamins, minerals, calcium, potassium, and vitamin D,” Bates says. “The removal of legumes also cuts out a source of protein – one of the most prominent protein sources for vegans and vegetarians.” Feren adds, “The second step is to reintroduce the ‘off -plan foods’ slowly and systematically and evaluate any consequent symptoms. However, there is no evidence to support the efficacy of the Whole30 diet. It is true some foods can cause reactions in the body or be malabsorbed, however, there are proven elimination and reintroduction diets that have the science to support their use.”

Alkaline diet

What is it?

The alkaline diet focuses on the consumption of alkaline-forming foods such as fruit, veggies, almonds, lentils, soy products, tofu, and sprouted grains. Foods to be avoided include sugar, coffee, dairy, and refined carbs. “Approximately 80 per cent of foods should be alkalising foods and 20 per cent can be acid-forming,” Bates says. Celeb fans include Elle McPherson, Victoria Beckham, and Gwyneth Paltrow.

Pros of the alkaline diet

“The alkaline diet is likely to cause some weight loss due to the focus on nutrient-dense, energy-poor fruits and vegetables. Limiting the consumption of red meat and processed foods encourages overall good eating habits,” Bates says. Fans of the diet also report they have clearer skin, increased energy levels, and better moods.

Cons of the alkaline diet

Bevan questions the diet’s healthy balance. “It can promote weight loss, but using the same formula that most fad diets do – restricting food groups,” she says. “We should be encouraging people to eat a wide variety of whole foods, not restrict foods we know have great health benefits such as fibre, protein and vitamins and minerals.”

Vegan diet

What is it?

The vegan diet excludes all animal products including meat, dairy, eggs, and honey. Followers may choose a vegan diet based on their values and/or for weight loss. “The popularity of vegan diets has definitely increased over the last couple of years, largely due to social media and the incredible food photography proving plant-based eating isn’t boring,” Bevan says. “More people are opting to eat more plants and avoid animal-based products. Due to this demand cafes, restaurants and supermarkets are providing more options than ever.”

Pros of the vegan diet

“A vegan diet is likely to result in weight loss due to significantly fewer kilojoules in fruit and veg versus meats and dairy,” Bates says. “A vegan diet is naturally low in cholesterol, therefore the risk of many diseases, in particular those related to the heart, is significantly reduced.” A vegan diet also has a lower environmental impact than meat-based diets.

Cons of the vegan diet

While we should all aim to include more plant-based foods in our diet, Bevan says it’s important to be aware of nutritional deficiencies. “Some nutrients to keep an eye on are iron, vitamin B12, and calcium,” she says.

Raw food diet

What is it?

“This diet involves ensuring 75 per cent of your diet comes from foods that are ‘raw’ – not cooked above 48°C, not pasteurised, and not refined or processed,” explains Bevan. “The raw diet is essentially a supercharged vegan diet as animal sources are eliminated.”

Pros of the raw food diet

The raw food diet promotes weight loss through the elimination of refined and processed foods. Other benefits include an emphasis on eating fruits, vegetables, nuts and seeds, “which are all rich sources of nutrients,” Bates says. “Also, uncooked fruit and vegetables retain their water-soluble vitamins.”

Cons of the raw food diet

Although proponents of the raw food diet claim it is more nutrient-rich than other diets, some experts are sceptical. “There is no evidence to suggest cooked food has fewer benefits,” Bevan says. “One issue with this approach, other than it being restrictive, is that it can be difficult to reach protein and iron requirements when foods such as legumes and soy are avoided.”

Did you know? “Low-carb approaches have recently gained appeal as dieters can often lose weight quickly. However, the research shows that people who reduce their overall kilojoule load lose the same amount of weight as those who adhere to a low-carb diet over a 12-month period.” – Joel Feren, media spokesperson for the DAA.

Dukan diet

What is it?

It’s a high-protein, low-carb diet designed by French nutritionist Pierre Dukan, and enjoyed by celebrity fans including Penelope Cruz, Jennifer Lopez and Gisele Bundchen.

Pros of the Dukan diet

“The Dukan diet encourages healthy habits through the elimination of refined and processed foods and alcohol,” Bates says. “It addresses a return to normal eating and doesn’t require weighing meals or counting kilojoules.”

Cons of the Dukan diet

Dietitians are sceptical about the plan, with the British Dietetic Association saying in 2011 that the regime is confusing and rigid, and has “no solid science behind it at all”. The Dukan diet is restricted to just 100 foods, with a heavy focus on protein, which, as Bates points out, can put pressure on the kidneys. It focuses on switching from burning carbs to burning fats (known as ketosis), which Bates says could have “unwanted side effects including bad breath, headaches and nausea.”