Why a mono-diet could be the secret to weight loss

As a nutritionist, I’m all about championing diet diversity. Eating a wide variety of foods, particularly plants, equals a broader mix of nutrients. It’s obvious, really. It’s the same message renowned food scientist Tim Spector has become well known for with his ‘30 plants a week’ approach to supporting gut health.

On top of that, 2026 analysis across the UK, US and Chinese cohorts found that healthier plant-based diets were associated with lower mortality rates. Research from the American Gut Project has also linked greater plant diversity with a flourishing microbiome, adding to the growing evidence that what we eat, and the variety of our diet, plays an important role in supporting long-term health and longevity.

That said, deciding what to eat can feel more complicated than ever. With conflicting advice on social media, a constant stream of new foods and ‘must-try’ influencer-led ingredients vying for our attention, it’s easy to see why taking some of the choice out of eating is appealing. I understand the merits of a somewhat repetitive diet pattern - a trend that’s been dubbed the ‘mono-style diet’, which focuses on rotating stock meals rather than cramming in as much variety as possible.

Benefits of the ‘mono-diet’

Eating the same foods on repeat is hardly a new concept. Victoria Beckham, for example, has spoken about sticking to a small repertoire of familiar foods (in her case: grilled fish, steamed vegetables and avocados). So, in an age when we’re bombarded with advice about the latest superfood, miracle ingredient and must-try diet, could having less choice actually make healthy eating easier?

“It reduces what psychologists sometimes call ‘decision fatigue’”

Jordan Haworth, a gastrointestinal physiologist at the Functional Gut Clinic, agrees that a mono-style diet can have its perks. “One advantage is that it reduces what psychologists sometimes call ‘decision fatigue’. This is where the quality of your choices gets progressively worse the more decisions you have to make. So, if for example your first two meals are consistently predetermined, you’re less likely to reach for the convenient, energy-dense option at night.”

A ‘boring’ diet could work particularly well for people who benefit from having a set choice of repeat meals and foods that they know work for them. “For example, someone with acid reflux may benefit from having a small repertoire of meals if they know they don’t trigger symptoms. Similarly, for sufferers of IBS following a low-FODMAP diet, short-term predictability can make symptoms easier to understand and manage,” continues Haworth.

Victoria Beckham is a fan of the mono-diet

PA Archive

And this simplicity could have a useful knock-on effect when it comes to weight loss. A recent observational study published in the journal Health Psychology found that participants who ate the same healthy foods every day lost more weight than those who varied their diets.

Downside of eating the same foods on repeat

Dr Flora Bailey, a GP and metabolic health specialist, points out the pitfalls. “The downside of eating exactly the same foods every day is that you can develop nutritional blind spots without realising it. A meal might be perfectly healthy in isolation, but relying on the same small group of ingredients long term can mean consistently missing other important nutrients such as iron, zinc, omega-3 fatty acids, calcium, folate and vitamin B12. You may also be getting a much narrower range of plant fibres which could compromise health,” she says.

One simple way to boost the nutritional value of your streamlined go-to meals is to think about how you prepare your carbohydrates. “Cooking and then cooling starchy foods such as potatoes, rice and pasta increases the amount of resistant starch they contain. Resistant starch is handled differently by the body than readily digestible starch, and has benefits for blood sugar control and gut health,” explains Dr Bailey. A chilled potato salad, pasta salad or cooked, cooled rice that’s then reheated are simple ways to put this into practice.

Cooking and then cooling starchy foods increases the amount of resistant starch they contain

PA Archive

If you’re eating the same meals on repeat, texture can be an easy way to keep things interesting without having to completely change what’s on your plate. It’s also thought to play a role in how satisfying a meal feels. “Texture is another overlooked factor. Foods that require more chewing naturally slow the pace of a meal, which can help with recognising fullness,” explains Dr Bailey. Try adding crunchy or chewy elements to your usual meals, such as raw vegetables, toasted seeds, nuts or wholegrains, to make a familiar meal feel more satisfying and encourage a slower pace of eating that supports weight loss.

You can keep meals predictable without making them nutritionally repetitive

You can keep meals predictable without making them nutritionally repetitive. Blending several ingredients into one meal is an easy way to introduce more variety while keeping your usual routine intact. “Use mixed frozen berries or make a diversity jar with different seeds, including sunflower, pumpkin, chia, flax and sesame. Your gut microbes also love spices, so use things like cinnamon, which has been shown to support metabolism and blood sugar regulation,” says Haworth. Try keeping a jar of mixed seeds ready to sprinkle over your usual meals, from porridge and yoghurt to tray bakes, pasta dishes and curries.