The Cambridge Diet


The Cambridge Diet, also known as The 1:1 Diet, is a very-low-calorie fad diet developed in the 1960s. In its various forms, it has specified a calorie intake between 330 and 1500 kcal per day. Food is principally in liquid form as meal replacement products or bars sold as part of the diet. While there is some evidence that these types of diets result in short term weight loss, there is little evidence of long term benefit.
The diet achieved popularity in the 1980s following its commercial launch in the USA in 1980 and the UK in 1984. Following the deaths of several dieters it was revised under pressure from the FDA. The UK National Health Service states that anybody following a diet of less than 600 kcal/day should be under medical supervision.
It was initially used in hospital weight loss programs. Since 2015 the company that makes the product is Cambridge Nutritional Foods Limited. There are concerns regarding the cost due to the fact that people must buy at least two weeks of product at a time. The diet is specifically not recommended by the American Academy of Family Physicians. it was renamed "the 1:1 diet", and has a calorie content of between 440 and 1500 kcal per day.

Versions

There are different versions of this diet in the US and the UK.

Development and reception

The Cambridge Diet was developed in 1960s by Alan Howard at Cambridge University, England. It was launched as a commercial product in the United States in 1980. The Diet was very popular in America but was also the subject of some controversy. It later came under scrutiny from regulators and health authorities after potential health concerns were raised. In the UK, the Cambridge Diet was launched in 1984. In 1987 a UK government Health Department report was critical of evidence submitted by Cambridge Nutrition - the working group responsible were not convinced by claims that the Cambridge Diet achieved protein sparing as well as conventional calorie restricted diets, and were concerned about conservation of lean tissue during dieting.
The Cambridge Diet is categorized as a very-low-calorie diet, and as a fad diet. Most of the meal replacement products sold as part of the diet are manufactured in the UK and include shakes, meal replacement bars, soups and smoothies.
In the early 1980s there were six documented deaths of people following the Cambridge liquid diet. Initially the diet started with a calorie intake of 330 calories/day, but under pressure from the U.S. Food and Drug Administration this was raised to 800 calories/day in the early 1980s. In 1985 Cambridge Diet Plan paid a six figure sum to settle a case brought by the family of a 31 year old woman who had died while following the Cambridge Diet. The FDA stated that eight such deaths were "potentially linked" to the Cambridge diet.
The diet has also been known as the Cambridge Weight Plan, and in 2019 it was renamed the "1:1 diet". It has 6 variants which specify a calorie intake of between 440 and 1500 kcal per day. the very-low calorie phase of the diet consists of 3 serving per day of meal-replacement liquid with a macronutrient composition of 43 g of protein, 42 g of carbohydrate and 8 g of fat, supplemented with micronutrients.
The British Dietetic Association list the possible adverse side effects as including "bad breath, a dry mouth, tiredness, dizziness, insomnia, nausea and constipation", and say that any person eating fewer than 600 kcal per day should be medically supervised. The diet is specifically not recommended by the American Academy of Family Physicians.