It’s the question which has stumped dietitians for decades — just what is the best weight loss diet?
Advocates of trendy ‘keto’ regimes, adored by Gwyneth Paltrow and Halle Berry to name but a few, have spent years insisting they know best, praising the strict, carb-free lifestyle for keeping them slim.
Others point to the ever-growing pile of studies demonstrating the health benefits achieved through intermittent-fasting, Hollywood’s newest obsession practised by the Kardashian clan, Chris Pratt and even Elon Musk.
Yet, according to AI, neither diet can claim the top spot.
Instead, MailOnline can reveal that accolade belongs to the Mediterranean diet — if you believe ChatGPT, the powerful chatbot that has become an online sensation due to its rapid research abilities.
And, for anyone wanting to test it out, you’re in luck. For it’s devised a weekly, step-by-step plan you can follow, packed with delicious meals built around chicken, steak and shrimp, as well as olive oil (obviously).
However, while some leading dietitians noted that ChatGPT correctly identified one of the ‘healthiest eating patterns on the planet’, others are not convinced, warning it failed to consider the diet’s nutritional profile, affordability or even practicality.
MailOnline asked the chatbot: ‘Can you please recommend me a singular diet plan and write me a dietary plan following this diet to help me lose weight? It must incorporate a specific regime for breakfast, lunch and dinner.’
This website then asked ChatGPT to provide a detailed calorie breakdown for each of the meals it recommended.
The Mediterranean — packed with vegetables, wholegrains and nuts and credited with keeping the Italians in good health— trumped them all.
It involves largely shunning dairy, red meat and alcohol, instead tucking into oily fish, nuts, seeds and pulses.
The regime is also rich in monounsaturated fats, from olive oil and nuts, and omega 3 fatty acids, from seafood, which support a healthy heart.
The AI bot provided an extensive seven-day food diary loosely based on the diet.
Breakfast options include Greek yoghurt with berries and nuts, avocado toast and a vegetable omelette, while chicken salad, lentil soup and goats cheese wraps were among the suggestions for lunch.
Dinner recommendations included grilled shrimp and vegetables, baked chicken with sweet potatoes and baked cod with quinoa.
Registered dietitian Nichola Ludlam-Raine praised the recommended diet for being rich in wholegrains and plant foods, including plenty of fruit, vegetables and healthy fats.
‘It’s great the fact that it has chosen a Mediterranean style diet, which is one of the healthiest eating patterns on the planet,’ she said.
‘I like the fact that portion sizes haven’t been included so that the person making the meal can decide on how much they have on the day, thus making it more tailored to them.’
However, she noted that it wouldn’t be suitable for those with coeliac disease, who can’t eat gluten.
Dr Duane Mellor, a renowned dietary expert, said the concept of using AI for dieting advice was ‘interesting’.
However, he slammed the suggested plan for not considering the nutritional profile of each meal, affordability and practically, as well as whether it fits a person’s tastes and preferences.
Following the ChatGPT recommended low-calorie diet may help with weight loss but it doesn’t reveal the nutrients in each meal, such as salt, sugar, fibre and protein, which have recommended intake for each day.
It also lacks detail on portion sizes and doesn’t factor in the ‘vital social aspects of food’, he said.
Dr Mellor, from Aston Medical School in Birmingham, said the plan was too vague for people to follow as some meals suggestions were arguably ambiguous.
He added: ‘It will draw on what are successful dietary approaches and it picked up Mediterranean diet and then it pulled together different dishes and meal ideas which fit that pattern.
‘This can result in some vague food items being included, such as avocado spread which could mean an alternative to margarine made with avocado oil or finely crushed avocado.’
Dr Aishah Iqba, an NHS medic and private wellbeing consultant, is worried about the effect AI can have on those living with an eating disorder.
She said: ‘When I asked ChatGPT to generate me a daily meal plan with 1,000 calories, I was given a reminder to speak to a dietician before making any changes.
‘However, it went on to produce me a diet plan.
‘I would worry how this could impact those with disordered eating if they can simply type a question in and have a plan generated for them.’
The NHS urges Brits to speak to their GP before starting a new diet or fitness regime.
Dr Iqba warned the one-size-fits-all approach to dieting by ChatGPT doesn’t address individual needs.
She added: ‘Science is showing to us more and more that while diet plays a part to weight gain, there are complex layers to it; our mental wellbeing, sleep, stress and general lifestyle all feed into the decisions we make around food.
‘A question posed to ChatGPT will have none of this information and therefore the output will be a blanket answer regardless of who the person is asking it.’
Advocates of trendy ‘keto’ regimes, adored by Gwyneth Paltrow (left) and Halle Berry (right) to name but a few, have spent years insisting they know best, praising the strict, carb-free lifestyle for keeping them slim
Others point to the ever-growing pile of studies demonstrating the health benefits achieved through intermittent-fasting, Hollywood’s newest obsession practised by the Kardashian clan, Chris Pratt (left) and even Elon Musk (right)
Chat GPT’s recommended diet plan:
Day One
Breakfast: Greek yogurt topped with fresh berries and a sprinkle of almonds. As well as a side of whole-grain toast with a small amount of avocado spread.
Lunch: Grilled chicken breast salad with mixed greens, cherry tomatoes, cucumbers, olives, and feta cheese. Drizzle with olive oil and lemon juice as dressing.
Dinner: Baked salmon seasoned with herbs and served with roasted asparagus and quinoa. Add a squeeze of lemon juice for extra flavour.
Day Two
Breakfast: Veggie omelette made with egg whites, spinach, tomatoes, and onions. Serve with a side of whole-grain bread.
Lunch: Whole-grain wrap filled with grilled vegetables, hummus, and grilled chicken strips. Add a side of mixed green salad.
Dinner: Baked chicken breast with lemon and herbs, served with a side of roasted sweet potatoes and steamed broccoli.
Day Three
Breakfast: Overnight oats made with rolled oats, almond milk, chia seeds and topped with sliced bananas and a sprinkle of cinnamon.
Lunch: Quinoa salad with cherry tomatoes, cucumber, red onion, Kalamata olives, and feta cheese. Drizzle with a simple dressing made of olive oil, lemon juice, and herbs.
Dinner: Grilled shrimp skewers with a variety of colourful bell peppers and onions. Serve with a side of whole-grain couscous and a green salad.
Day Four
Breakfast: Smashed avocado on whole-grain toast topped with sliced tomatoes and a poached egg.
Lunch: Lentil soup with a side of mixed green salad dressed with olive oil and vinegar.
Dinner: Grilled lean steak with roasted brussels sprouts and a small portion of wholegrain pasta tossed with olive oil and garlic.
Day Five
Breakfast: Spinach and mushroom frittata made with egg whites. Enjoy with a side of sliced melon.
Lunch: Mediterranean-style salad with mixed greens, cherry tomatoes, cucumbers, chickpeas, olives, and feta cheese. Dress with olive oil and balsamic vinegar.
Dinner: Baked cod with a tomato and olive tapenade, served with sautéed courgette and quinoa.
Day Six
Breakfast: Whole-grain oatmeal topped with sliced peaches, a sprinkle of almonds, and a drizzle of honey.
Lunch: Grilled vegetable and goat’s cheese wrap with a side of mixed green salad.
Dinner: Grilled chicken skewers marinated in lemon and herbs, served with grilled vegetables and a side of whole-grain couscous.
Day Seven
Breakfast: Greek yoghurt with honey, sliced almonds and fresh berries. Enjoy with a side of whole-grain toast.
Lunch: Quinoa-stuffed bell peppers with a side of Greek salad.
Dinner: Baked white fish (such as tilapia) with a lemon and herb crust, served with roasted butternut squash and a green salad.
From Penélope Cruz’s loved Mediterranean diet to the life-extending FRUIT-heavy regime and even FASTING, experts reveal three of the best, science-backed weight loss regimes
Thoughts of cutting back kick in for many shortly after Christmas, as part of a ‘new year, new me’ drive.
But the swathes of different dietary advice can be overwhelming.
The much-hailed Mediterranean — packed with vegetables, wholegrains and nuts — is labelled the diet that ‘trumps all others’ by some experts. A-listers like Penélope Cruz and Cameron Diaz swear by it.
Other science-backed options include diets that promise to make you live longer to eating patterns that see you avoid food for 16 hours a day.
MailOnline asked four top experts to share their thoughts on the best diets for losing weight in January.
Mediterranean diet
It’s hailed by doctors and scientists for its menu of fruit, vegetables and wholegrains.
The Mediterranean diet also involves largely shunning dairy, red meat and alcohol, while tucking into oily fish, nuts, seeds and pulses.
A plethora of evidence suggest that it boosts heart health because it cuts out saturated fat — allowing for only a low consumption of butter, fatty meats and pastry.
It is also rich in monounsaturated fats, from olive oil and nuts, and omega 3 fatty acids, from seafood, which support a healthy heart.
Research has also linked the diet to a low risk of type 2 diabetes and strokes. Scientists believe these effects are down to the diet reducing inflammation inside the body, as well as blood sugar and BMI.
Professor Tim Spector, author of Food for Life and Spoon Fed, told MailOnline that science ‘points to one dietary pattern that trumps all other diets for all outcomes’.
He said: ‘The Mediterranean diet (MD), seamlessly brings together many aspects of what to eat, when to eat and how to eat, with plenty of scientific evidence to back it.
‘The Mediterranean diet is not to be underestimated.
‘Many think it is only relevant to European cuisines and some might even be mistaken in thinking it includes eating lots of refined carbohydrates like pasta.
‘When in actual fact it’s a dietary pattern and not a prescriptive list of ingredients.
‘For instance, the MD is characterised by the majority of our energy coming from whole plants, and includes whole grains, beans, nuts, spices, herbs and seeds as a major players.
‘It does not specifically recommend pasta and pizza, but it does recommend using extra virgin olive oil as a main source of dietary fats, with that being the only truly “prescriptive” ingredient, and with good reason.’
Olive oil is a source of monounsaturated fat, which helps maintain levels of ‘good’ cholesterol and reduces levels of ‘bad’ cholesterol.
Meanwhile, saturated fat — such as butter, red meat and cakes — have been deamonised for decades because of its link with high cholesterol and heart disease.
Professor Spector, who also co-founded the ZOE app, added: ‘The MD importantly also includes lifestyle factors that are crucial for good health.
‘Being active every day and enjoying our meals with family and friends is an often overlooked component but one that we must try to integrate into our everyday life.’
While a good diet offers some health benefits, staying active and social — traditionally an important part of the Mediterranean lifestyle — is also vital.
Longevity diet
Scientists have long been on the hunt for ways to extend life and healthy years.
A diet rich in wholegrains, such as brown rice, legumes, such as black beans, and plant-based protein, such as chickpeas, is one way to do this, researchers say.
The ‘longevity diet’ also involves fasting for 12 hours a day and entirely ditching red meat — although those following it strictly are still allowed ‘some’ of their favourite treats.
Some fish is allowed and chicken intake has to be kept ‘very low’. Sugar and refined grains — such as white bread, pasta and cereal — need to be scaled back.
The diet is the brainchild of researchers from the University of Southern California, who reviewed hundreds of studies on nutrition over the last decade in their quest to unearth the diet that ‘offers the best chance of living for longer and healthier’.
Following this diet can ‘delay ageing’ and reduce the risk of developing age-related diseases, including diabetes and cancer, the researchers said.
Lead author Dr Valter Longo, an expert in ageing and biological science, argued ‘its not a dietary restriction intended to only cause weight loss’.
Instead, it aims to slow ageing and ‘aid in avoiding morbidity and sustaining health into advanced age’.
A plethora of evidence shows these eating patterns would encourage healthy cell function and ward off obesity, diabetes and cancer.
Dr Romina Inés Cervigni, director of Dr Longo’s research foundation, told MailOnline that the macronutrients in a diet — especially proteins and sugars — can ‘directly activate and increase’ the levels of some hormones and genetic pathways ‘that are associated with accelerated aging’.
‘Ageing is considered the main risk factors for age-related diseases such as diabetes, cancer, cardiovascular, and neurodegenerative diseases,’ she said.
A balanced diet that promotes healthy weight and supports pathways in the body can reduce the body’s ageing while extending lifespan and healthy years of life, Dr Cervigni said.
The benefits of the diet are larger the earlier it is adopted but even starting at 80-years-old can increase a person’s lifespan by three-and-a-half years, she predicted.
US researchers have set out a ‘longevity diet’ — one that can offer the best chance of living for longer and healthier — after reviewing hundreds of studies on nutrition conducted over the last century. They say the ‘optimal diet’ should include a lot of legumes (pictured) — such as lentils and beans — as well as whole grains and vegetables
Intermittent fasting
The 5:2 and 16:8 diets have soared in popularity in recent years, and for good reason, experts say.
Both are based on intermittent fasting, which involves eating healthily at certain times and not eating at others.
The 5:2, fashioned by Mail health guru Dr Michael Mosley, involves eating little — around 500 to 800 calories — for two days per week and following a healthy diet for the remaining five days.
The 16:8 involves fasting for 16 hours every day and eating healthily within an eight-hour window, normally between 10am and 6pm.
Although this covers most of the waking day, it rules out late night snacking.
Some studies suggest it helps with weight loss, which has the obvious knock-on effects for those who are overweight or obese, such as a lower risk of developing serious illnesses, such as coronary heart disease and diabetes.
It has also been linked to living longer and a reduced risks of some cancers and neurodegenerative disorders.
However, others have found that fasting is not more effective than dieting seven days per week — with scientists warning the approach is ‘no magic bullet’.
But Dr Katie Myers Smith, a chartered health psychologist and senior research fellow at Queen Mary University of London, told MailOnline: ‘Fasting diets are a popular dietary approach most likely due to its simplicity.
‘The 5:2 diet requires calorie restrictions on just two days of the week which for many people is a much more manageable approach.
‘Weight loss is realistic (i.e. a pound per week) which make it more likely that the diet be maintained in the longer term.’
Psychobiotic diet
Even those not looking to shed weight can switch-up their diet for health benefits.
A psychobiotic diet, which involves eating lots of fibre and fermented foods, can lower stress and boost sleep, according to emerging research.
The approach involves eating six to eight servings of fruit and vegetables per day that are high in prebiotic fibre, such as onions, leeks, cabbage, apples and bananas.
Those following it also consume five to eight servings of grains per day and three to four legumes per week, as well as two to three fermented foods daily — such as sauerkraut, kefir and Kombucha.
Researchers at University College Cork, who studied participants who previously followed a relatively low-fibre diet, found that those who adopted the plan for four weeks saw their stress drop by around a third and sleep quality improve.
The diet is thought to work by feeding the trillions of microbes in the intestines, which are in constant communication with the brain through a mechanism known as the gut-brain axis.
Professor Ted Dinan, emeritus professor of psychiatry at the university, told MailOnline: ‘I would recommend at least two daily portions of yogurt, kefir or kombucha.
‘In terms of prebiotics, at least two sources of fibre are required, such as Jerusalem artichoke and leaks.
‘A non fibre source of prebiotics is desirable, such as an oily fish.’