St. Joseph's Three-Day Diet

St. Joseph’s three-day diet, essentially a three-day fad diet, may produce weight loss in a short period of time. Three-day, restricted-calorie diets often use the names of medical facilities such as St. Joseph’s Hospital; however, their true origins remain unknown. Most three-day diets promise a weight loss of up to 10 lbs. in three days, according to Consult your doctor before beginning St. Joseph’s Three-Day Diet or any other three-day diet.

Three-Day Diets

The majority of three-day diets are designed for short-term use only. They provide a daily menu of specific foods that purportedly chemically react with each other to boost metabolism and burn fat. After following a restricted-calorie diet for three days, most plans recommend taking a break for two to five days and then continuing this pattern until achieving weight loss goals. Many three-day diets restrict calories to 1,000 per day, but some versions only allow 700 calories daily. While three-day diets reportedly help with temporary weight loss, a lack of scientific evidence exists to prove their effectiveness.


While various three-day diet programs exist, most contain similar menu items and guidelines such as allowing the use of salt, pepper, mustard, vinegar, herbs and other seasonings. You can usually drink coffee or tea with each meal and can substitute specified vegetables and fruits, but cannot snack between meals. One common day-one menu begins with a breakfast of half of a grapefruit and a piece of dry toast with 1 tbsp. of peanut butter. You consume 1/2 cup of tuna and a piece of dry toast for lunch; and consume 3 oz. of lean meat, 1 cup each of green beans and carrots, one apple and 1/2 cup of vanilla ice cream for dinner. Days two and three contain similar menus items, but substitute foods such as two hot dogs for 3 oz. of lean meat.


Although the St. Joseph’s Three-Day Diet may provide a simple, short-term, low-cost and easy way to lose weight, a good diet must be sustainable. Three-day diets fail to give users the tools necessary to keep weight off, such as a healthy lifetime diet and an exercise regimen. A three-day diet may produce quick, but short-lived weight loss results. Some three-day diets suggest that you return to your normal eating habits after losing weight. In addition, the pounds dropped after this short diet most likely occur from water weight loss, according to Diet Health.

Health Risks

Extended use of diets with severely restricted caloric intake, such as the St. Joseph Three-Day Diet, can pose serious or deadly health risks. The number of daily calories consumed on a three-day diets falls significantly under the approximately 2,000 calories per day recommended by the 2010 Dietary Guidelines for Americans. People who misuse low-calorie diets may increase their risks of malnutrition -- or the imbalance of nutrients needed and those consumed. According to Merck Manuals, fewer than 1,000 calories a day produces inadequate nutrition -- causing the body to obtain nutrients from its own fat stores, tissues and organs -- which can result in serious health problems and death.