As if life wasn't hard enough for followers of the strict ultra-low-carbohydrate ketogenic diet, health experts have ranked the regime last in an analysis of popular food plans.

Devotees to the ketogenic diet consume between 15 to 100g of carbohydrates per day, instead topping up their meals with foods high in fat and protein. To put this into perspective, one apple contains 25g of carbohydrates on average and the NHS recommends that a person aged between 19 and 64 can eat at least 260g carbohydrates a day. The "keto" diet sends the body into a state of ketosis, where fat is broken down into ketones as fuel.

The average keto diet consists of lean meat, eggs, seafood such as fatty fish, low-carb vegetables like cauliflowers and courgettes, dairy products including butter and cream, avocados, olive oil, as well as nuts and seeds. While most fruits are considered too high in carbohydrates, small amounts of berries such as raspberries and blueberries are allowed.

Experts enlisted by the US News and World Report, which publishes trusted rankings and consumer advice, came to their conclusion by assessing diets according to how easy they were to follow, the scientifically proven nutritional benefits, safety, effective weight loss, and protection against chronic illness such as diabetes and heart disease. Keto ranked last, below Paleo – which hails food eaten by our Paleolithic ancestors – and the raw food diet (which does involves exactly what you might imagine it to).

The experts said that keto isn't unsafe in the short term. However, they were concerned by recommendations for 70% of calorie intake to come from fats, and highlighted that it may be tough to stick to.

Adherents of the keto diet may also not know it was first designed as a treatment for children who do not respond to epilepsy medication, NHS paediatric dietitian Clare Thornton-Wood told IBTimes UK.

"It is not recognised as a healthy way to lose weight or a diet that is beneficial to health," she said. "When it is commenced in children it is closely supervised by a consultant and dietitian, blood results are monitored very frequently and intake adjusted accordingly. It is often commenced in an inpatient setting,"

"The diet can have unpleasant side effects such as nausea and general digestive upset, lack of energy, decrease in exercise performance and bad breath. Long term there could be an increased risk of cardiovascular disease and kidney damage," added Thornton-Wood.

"There is no doubt about it – we eat too much food hence the obesity crisis and carbohydrate is one of those foods which we consume in excess," commented dietitian Aisling Pigott to IBTimes UK. "Many people find these diets make them more aware of the large volumes of carbohydrate they were eating previously."

However, she chimed that it is unsustainable for most people, and by promoting a free-for-all approach with fats and protein it does not address a person's complex relationship with food and eating. In the likely event that a person gives up and returns to eating carbohydrates, it can lead to increased weight gain.

So, what should we be eating? The DASH and Mediterranean diets, according to the experts. Developed by the National Heart, Lung and Blood Institute, DASH heavily features fresh vegetables, fruits, and whole-grain products, poultry and fish in moderation.

Ranking joint second, experts praised the largely similar Mediterranean diet as "immensely sensible" with its emphasis on fruits, vegetables, olive oil, fish, and minimal levels of red meat, sugar and saturated fat.

Thornton-Wood agrees that the Mediterranean diet is the smartest way for the average person to eat. "There are a number of large published studies demonstrating the beneficial health benefits of following a Mediterranean diet, particularly in terms of cardiovascular health and weight control," she said.

Piggott, however, reminded that while the Mediterranean diet is indeed healthy, ultimately the best diet is the one a person can follow.

"The best diet is one that suits you. If you dislike Med food, then why would you eat food that you dislike? There is no such thing as the 'best' diet.

"The best advice is to examine and explore your relationship with food, consider portion sizes relevant to your energy requirements and have lots of fresh, unprocessed meals where possible."