Say no to these food and weight-loss trends

Some diets are designed to deliver more side effects than long-term results. Discover how to rate a weight-loss diet you may be considering trying, as well as a handful that deserve a hard no from the get-go.
Published 2 August 2023 | Updated 9 July 2024

Given the fact that two out of three adults living in Australia say they’re trying to lose weight, it’s probably not surprising that 25 per cent of Australians embark on a new weight loss eating plan each year.

Worryingly though, fewer than seven per cent of people in Australia eat what’s considered a ‘healthy balanced diet’, so it’s clear that something is going wrong. In other words, we might be trying to eat better to lose weight or improve our health, but the reality is, most of us are falling short. One explanation could be fad diets that have not only been linked to weight regain, they can also cause nutrient deficiencies due to how restrictive they are about what can and can’t be eaten.

5 fat diets that may do more harm than good

Weight loss eating plans come in all shapes and sizes and not all of them are bad – or fads! – but if you’re considering trying one of the following to lose weight or improve your health, it may be time for a rethink.

1. The raw-food diet

The raw-food diet ranked lowest across the board in the 2023 US News & World Report's annual diet ranking.

As its name suggests, you can only eat food that’s raw, the theory being that it’s healthier. So, anything that’s been cooked, processed or exposed to heat is off the menu.

Unsurprisingly, this diet is not only very restrictive, it can lead to nutritional deficiencies – which makes sense when you consider that even good-for-your-gut legumes and healthy grain-based foods need to be cooked before they’re eaten.

It’s also true that some foods actually develop healthy properties when they’re cooked. For example cooked tomatoes contain more of an antioxidant called lycopene than raw ones.

2. The carnivore diet

In the midst of a push towards a plant-based style of eating, this diet is essentially the exact opposite. Everything from fruits and vegetables to grains, nuts and seeds as well as legumes are excluded, so the only things that are allowed on the carnivore diet are meat and animal products. The claim is this is beneficial for health because humans are designed to eat animal foods, not plant foods.

But as well as agreeing that the carnivore diet doesn’t in fact, deliver nutritional benefits, experts also say it’s unhealthy. Long-term concerns even include the fact that it may bump up the risk of both cancer and heart disease.

3. The wheat belly diet

This one makes wheat – or more accurately gluten – the enemy, blaming it for both weight gain and a range of other health problems.

It’s on the back of a trend that saw the idea that gluten-free foods are somehow healthier and can lead to weight loss. As a result, a study shows that one in four Australians actively avoid gluten for either weight control or general health, even though the evidence to support those outcomes doesn’t stack up.

In reality, the wheat belly diet may deliver some weight loss simply because it’s highly restrictive (other non-wheat-based foods, like potatoes and legumes, are also avoided) not because it eliminates gluten. And, eliminating the many types of wholegrains that contain gluten can lead to deficiencies in everything from iron and zinc to vitamins D and B6.

4. The FODMAP diet

Developed by Monash University, it’s one of the most well-researched diets around – and it’s incredibly effective for the people it is designed for, which are those living with irritable bowel syndrome, or IBS.

One in seven Australian adults are thought to have IBS and research shows that following the FODMAP diet reduces symptoms for 75 per cent of them.

But in recent times self-proclaimed health gurus and Instagram influencers have wrongly labelled the FODMAP diet as being good for weight loss, as well as a treatment for a range of other health conditions.

While weight loss may be an unintended side effect of this eating plan, which reduces the intake of foods that contain five types of naturally occurring, fermentable sugars, following it long term may lead to a shortfall in important nutrients. In fact, it’s not even considered a lifetime diet for people with IBS.

5. Clean eating

There isn’t ‘one way’ to do this, but this eating plan typically involves avoiding refined and processed foods as well as those that contain artificial ingredients, in favour of whole, natural, unrefined and unprocessed foods.

On the surface, clean eating probably sounds pretty good, but when you get down to the nitty gritty, it’s actually really restrictive, eliminating certain food groups entirely.

It also labels some foods as ‘impure’ or even ‘dirty’, which can trigger feelings of guilt when you eat something ‘bad’. This can encourage a negative relationship with food and, in extreme cases can even contribute to the development of eating disorders.

How to spot a fad diet

Fad weight-loss diets are all slightly different, but they typically have some common features, including that they often:

  • have a list of foods that you are and aren’t allowed to eat
  • label one nutrient or food group as ‘the problem’ when it comes to weight gain and poor health
  • promote one nutrient or food group as the solution
  • promise weight loss results that are fast and easy to achieve
  • don’t have the research to back up any weight-loss or health-related claims
  • involve buying expensive supplements, shakes and pills

Look for sustainability and science

Fad diets might deliver rapid, short-term weight loss, but because the restrictions they involve aren’t sustainable long term, as well as creating nutritional deficiencies or worse, they typically lead to a yo-yo dieting cycle as you move from one diet to the next.

Instead, for good health and long-term weight loss, choose and stick to a food plan that’s liveable, where no food – or food group – is off limits and that doesn’t promise a quick fix.

WeightWatchers® not only offers all this, it also has more than 145 studies published about it. One of the latest compared 141 weight-loss programs and, as well as identifying WeightWatchers as having clear evidence to support its efficacy, it also singled the program out as having the largest number of randomised clinical trials evaluating its effectiveness.