Whenever Mikhail Goldreyer meets new people, he always asks them the same question: "How old do you think I am?"

"They are usually off by about 10 years," Goldreyer, 43, says proudly. "Most people think I am in my early 30s. When I walk down the street with my 14-year -old son, they think we are brothers." The way Goldreyer tells it, his youthful looks are the result of a combination of fasting and some strategic surgery that lengthened his legs a little. Actually, a lot. With a procedure developed by Gavril Ilizarov, an osteopathic surgeon in Volgograd who died in the 1970s, Goldreyer managed to grow six centimeters in 1993.

Now he considers himself a walking advertisement for the Ilizarov Method of Growth and Rejuvenation, which is essentially cosmetic surgery from the inside out. It may be a drastic measure, but the results are undeniable: He is taller, thinner, and does not look a day over 30.

Until two years ago, Goldreyer, an electrical engineer by trade, served as a deputy in Volgograd's local soviet. He had always been interested in medicine and in exercise as a way of staying healthy, he said.

Then he read in a newspaper that with the Ilizarov method, doctors could reconstruct shattered legs without using metal or plaster, and that in an experiment 20 years ago, a doctor lengthened the legs of a healthy groom who was ashamed of being too short for his bride.

"I suddenly realized that nothing could prevent a mature, independent person over 30 from gaining strength, health and a new appearance this way," Goldreyer said.

So he went ahead and got the operation, which involved dividing in two the fibula, the outer bone that extends from the knee to the ankle, and then stretching the leg with an external brace and allowing the two sides of the bone to grow and fuse naturally.

The bone grows at the rate of one millimeter a day, according to Goldreyer, and once the brace is taken off, you can walk normally after about 10 days.

While Goldreyer's appearance has certainly changed, it's not quite certain that it was for the better. He is indeed taller than he used to be (176 centimeters rather than 170), but last week, after 18 days of fasting at Moscow Clinic No. 63, he looked frail and a bit peaked. Young, perhaps, but not particularly healthy. And although he and his doctor - Mikhail Yegorov, one of Ilizarov's disciples - claim that there are no side effects to the leg operation, Goldreyer does walk with an odd gait.

"He did not tell me he was going to get this operation," said Goldreyer's mother, Lyubov, over the phone from Volgograd. "He just came over one day and showed me. Now I think it is okay, but his new height is not really very useful." Not so, says Goldreyer. Yegorov has organized a sanatorium for people who want to get taller and look younger, and Goldreyer has offered to serve as a walking advertisement for it. Allegedly there is already plenty of interest in the Ilizarov method; Goldreyer claims that he and Yegorov have received "bags full of letters." from all over the former Soviet Union, Europe and North America.

"One American offered $10,000 for the leg operation," Goldreyer said, and then added defensively, "I can show you the letter. For this man, we can provide everything, by Western standards. And he will get his centimeters."

Goldreyer seems a bit touchy about the fact that people don't always take him seriously. He carries a video with him that shows him receiving the operation and going through treatment afterward. When he talks about the Ilizarov method, he uses the words "science" and "proof" a lot.

As far as Goldreyer is concerned, he is walking tall, and modern technology is the reason why. "I want to show that it is medical, not magical," he said.