Scientist Study Harmful Effects Of Protein Diet

Med School researchers are currently conducting animal experiments in an effort to isolate the effects of the potassium deficiencies that may result from unsupervised adherence to a new "fad" diet--predigested liquid proteins--Dr. George L. Blackburn, director of the nutrition support service at New England Deaconness Hospital, said yesterday.

Blackburn and three other researchers began the experiments on rats this fall following the deaths of 12 persons using the liquid protein weight-loss diet. Blackburn said yesterday he believes potassium deficiencies were partly or wholly responsible for the deaths.

Liquid protein is sold in health food stores and pharmacies without a prescription. The daily dosage is six tablespoons, which provides about 180 calories. Dieters consuming the protein exclusively may lose five to ten pounds a week.

Vitamin and mineral supplements must be taken with the liquid protein, which does not contain them, Blackburn said. The protein is safe, but exclusive consumption of the liquid for long periods of time may result in serious mineral deficiencies, Blackburn said.

A Radcliffe student who has used the diet intermittently during the last six months said yesterday the orange- and cherry-flavored liquid protein tastes terrible, but is very effective in helping to shed pounds. She complained of small side effects--muscle spasms and teeth "feeling loose," and said she is afraid the diet "isn't really healthy."

Salesmen at the General Nutrition Center store on Holyoke St. said yesterday they sell about two quarts of liquid protein each day. Most customers learned about the diet through a paperback bestseller, "The Last Chance Diet," they said.