Friday 1 March 2013

The Cambridge Diet



The Cambridge diet is a commercial very-low-calorie diet (VLCD). The diet was first used only in weight-loss clinics in the United Kingdom. In the early 1980s, the products associated with the diet (powder mix, meal bars, and liquid meals) started selling commercially in the United States and the United Kingdom. Formulations of the Cambridge diet in the United Kingdom differ from that sold in the United States. In both the United Kingdom and North America, the Cambridge products are available only from distributors; they cannot be purchased over the counter at pharmacies or supermarkets.

Origins

United Kingdom and Western Europe

A scientist at Cambridge University in England, Alan Howard, initiated the research that eventually lead to the development of the Cambridge diet in the 1960s. Howard became interested in obesity as an increasingly common nutritional problem. He worked together with Ian McLean-Baird, a physician at the West Middlesex Hospital, to create a formula diet food that would allow people to lose weight rapidly without losing lean muscle tissue, create a mild ketosis (a condition in which the body begins to use fat rather than carbohydrates as a source of energy), and contain enough vitamins, minerals, and micronutrients to maintain health. Howard and Mc-Lean Baird also organized the first national symposium on obesity in the United Kingdom, which was held in 1968.
The formula that satisfied the researchers” goals was successful in helping people in hospital obesity clinics lose weight, but was not particularly appetizing. The researchers collaborated with food technologists to improve the flavor of the formula. After further testing with clinic patients, the Cambridge diet was marketed commercially in the United Kingdom in 1984, four years after it was available in the United States. In 1985 the Cambridge diet became available in Germany, France, and the Scandinavian countries, and in 1990 in Poland and Eastern Europe. The British company, Cambridge Manufacturing Company Limited (CMC), which manufactures the diet products as well as the Cambridge Health and Weight Plan, were owned by the Howard Foundation between 1982 and 2005, a charitable trust established by Alan Howard to offer scholarships to international students and to fund research in obesity and nutrition. In 2005 the Cambridge Manufacturing Company was sold to its three senior managers and became Cambridge Nutritional Foods Limited.
The present Cambridge diet products available in the United Kingdom are sachets (packets) of powder, Mix-a-Mousse granules, liquid meals, and meal bars. The sachets are intended to be mixed with a half-pint of water (hot or cold) to produce a shake or soup. The sachets, which provide about 138 calories, are sold in boxes of 21 servings, a week’s supply. There are 12 different flavors including banana, mixed fruit, and chicken mushroom. The dieter may also purchase Mix-a-Mousse granules that add 20 calories to the powdered formula but give it a thicker texture. The liquid formula is available in a ready-to-drink version packaged as Tetra Briks—sealed cartons with straws. Tetra Briks come in banana or chocolate flavor. There are four flavors of chocolate-covered meal bars (caramel, chocolate, orange, and toffee), one of which can be consumed each day.
Each sachet or liquid formula contains enough nutrients to be used as a complete meal. The meal bars can replace a meal as well but have extra carbohydrates and should only be eaten once a day. The Cambridge diet products can be consumed exclusively as meal replacements or used in conjunction with regular food (e.g., sachet for breakfast, Tetra Brik for lunch, and normal dinner).

Description

British version

The British version of the Cambridge diet cannot be used without the supervision of an official counselor, who “provide[s] a personal screening, advisory, monitoring and support service.” The counselors are trained and accredited by the company, and must follow a code of conduct in their dealings with customers. According to the company, most counselors are people who have successfully used the Cambridge diet themselves.
The British version of the Cambridge diet is for adults over the age of 16 and has four stages:
  • Preparation: The dieter is asked to reduce food intake gradually over a week to 10 days before beginning the diet.
  • Stabilization: After four weeks on the Sole Source program, the dieter can add a meal of 3 oz lean white fish or poultry, cottage cheese, and a portion of green or white vegetables to the basic Cambridge meals for a total of 790 calories per day. The dieter can then return to the Sole Source regimen for further rapid weight loss. There are other options allowing the dieter 1,000-1,200 calories per day that are better suited for gradual weight loss.
  • Weight maintenance: Begins at an intake of 1,500 calories per day.

American version

The American version of the Cambridge diet is divided into five separate programs:
  • Regular: Designed for a weight loss of 2-5 lb per week, the Regular Program provides 820 calories per day: three servings of Cambridge Food for Life formula plus one 400 calorie conventional meal. The dieter is advised to drink a minimum of 8-10 8-oz glasses of water each day. Tea and coffee are allowed, but not as substitutes for the water. There is no stipulation that the Regular program is limited to four weeks.
  • Fast Start: Similar to the British Sole Source program, the Fast Start program is to be followed no longer than two weeks at a time. The dieter is advised to return to the Regular Program and contact a physician if they experience headaches, nausea, or vomiting.
  • Physician-Monitored: Recommended for persons who need to lose 30 lb or more, or who are under a doctor”s care for other medical conditions. It is essentially the British Sole Source program with the added provision that the dieter should switch to the Regular Program when he or she is 10-15 lb from their goal weight.
  • Maintenance: Uses the Food for Life nutrition formula as a foundation, while adding conventional foods until a caloric intake is determined to maintain an ideal weight.
  • Lifetime Nutrition: The Food for Life company recommends using the Cambridge diet products as meal substitutes for one or two meals a day, or as snacks indefinitely. This maintenance program is not endorsed by any government agency.

Function

The Cambridge diet claims to be a flexible plan that can be used as a VLCD for rapid initial weight loss and then modified to serve as a maintenance diet.

Benefits

The Cambridge diet offers a rapid initial weight loss that compensates (for some dieters) the low calorie intake and other food restrictions. The American version also offers a peer support network and a self-instruction program based on cognitive behavioral therapy (CBT) called Control for Life.

Precautions

People under a physician’s care for high blood pressure, kidney or liver disease, diabetes, or who need to lose more than 30 lb should consult their physician before starting the Cambridge diet or any VLCD The Cambridge diet should not be used by adolescents under the age of 16, and should be used by elderly persons, pregnant women, or nursing women only with caution.

Risks

VLCDs in general should not be attempted without consulting a physician, and the Cambridge diet is no exception. The diet is not suitable for people whose work or athletic training requires high levels of physical activity. One physical risk from this diet, as from other VLCDs, is an increased likelihood of developing cholelithiasis, or gallstones.
There is also some financial risk to using the Cambridge diet. Although the American website states that the Physician-Monitored version is less expensive than VLCD hospital programs, all forms of the Cambridge diet cost $95–100 for a 15-day supply of the Original 330 Formula or $85–89 for a 15-day supply of the Food for Life formula. A case of six cans of the Original 330 Formula, supplying a total of 126 servings, is about $160. Although the cost per meal is between $1.25 and $1.45, the fact that the dieter must purchase at least a two-week quantity at a time is a risk for people who may not like the products well enough to remain on the diet.
A common criticism of the Cambridge diet, as of all VLCDs, is that it does not teach the dieter how to make wise food choices or the other lifestyle changes necessary to maintain weight loss. The British website states rather defensively, “To these armchair critics [the Cambridge diet] is just another fad diet. Nothing could be further from the truth as anyone can vouch.