LAST January, Wesley Johnson looked in the mirror and saw what had been staring back at him his entire life: skin and bones.

At 5-foot-10 and a mere 133 pounds, Mr. Johnson, 26, a laboratory research assistant in Columbus, Ohio, was mortified by his inability to gain weight. His friends scoffed: We wish we had your problem! Others were skeptical: Why don't you just eat more?

Mr. Johnson had tried to bulk up before. Eight years earlier, when he was a student at the University of Mississippi, he was inspired to work out by his roommate, a 6-foot-2, 245-pound bodybuilder. "My arms were twigs," Mr. Johnson lamented. He collected books on weight lifting for guidance, reading many half a dozen times, and he lifted for two hours six days a week.

In two years he added 15 pounds of muscle. But then his weight gain stalled. He was bigger, but not big enough.

Finally last year Mr. Johnson went online and found what he couldn't get from any Arnold Schwarzenegger fitness manual: advice from people who also had trouble gaining and keeping muscle. He learned from discussion groups and blogs to take rest days between workouts to give his muscles time to recuperate and grow. He began carrying a kitchen timer so he would remember to eat six or seven times a day.

Some days he took in as many as 8,000 calories, snacking on pork chops, peanut butter, Little Debbie brownies and whey protein shakes. Within four months of starting his new regimen, Mr. Johnson gained a total of 41 pounds. He started a blog,, to publicize his progress as well as two online discussion groups aimed at helping other skinny guys put on as much weight as he had.

While most Americans battle the bulge, a small but persistent minority fight to keep the pounds on. Two percent of adults are underweight, according to a 2004 report by the National Center for Health Statistics.

And although skinny people may elicit little sympathy from their pudgy peers, their problems are real: They cannot fill out suit jackets, they are embarrassed at the beach, and they have to put up with people asking if they have an eating disorder. They want to transform their bodies not because their health is at risk, but to avoid standing out.

Once strangers to the gym, underweight men and women known as "hardgainers" by bodybuilders are now enlisting nutritionists and trainers who specialize in bulking up, as well as former bean poles like Mr. Johnson who have become online bodybuilding gurus. The skinny are also discovering one another on the Web, sharing everything from protein bar recommendations to bench press advice. Unlike some weight lifters who resort to steroids, many of this new breed of too-thin gymgoers are adamant about increasing their girth naturally.

The message boards on, for example, are filled with hardgainers keen to eat and exercise their way to a bulkier body. They are tired of the names ("twice in one night was called ANOREXIC!!!"); tired of dating woes ("Had a young lady once who told me I would never be able to have sex with her because she'd break me in two"); and most of all tired of their appearance ("I HATE having thin legs, thin wrists and ankles").

Each of the 800 members of paid $97 to join a program detailing how Anthony Ellis, its founder, gained 35 pounds in 12 weeks. "I really wanted to create a base for people who were looking to gain weight and didn't know where to go," Mr. Ellis said. "When I was starting out, I could only ask the naturally big guys at the gym for help."

People also pay for muscle-gaining advice at, which is run by Sean Nalewanyj, a bodybuilder who used to be rail thin. Free discussion groups are offered at Web sites like and And J. P. Clifford, a salesman in Kansas City, Kan., doles out free suggestions based on his personal experience at

Advice on how to gain weight is so plentiful that some fitness experts say there is a risk that people will be confused. "Now more than ever before there's a community in real life and on the Web for people who want to gain weight without steroids," said John Berardi, a nutritionist and an author of "Scrawny to Brawny: The Complete Guide to Building Muscle the Natural Way." "But sometimes I think it's information overload."

Many online weight-gaining regimens are designed by people whose expertise comes not from medical training but from personal experience. "These programs haven't been studied under laboratory conditions," said William J. Kraemer, a professor of kinesiology at the Neag School of Education at the University of Connecticut in Storrs. "I'd be wary of any that promise fast results."

Dr. Kraemer found the three-month time frame of Mr. Ellis's program far too short. "Maybe in six months you'd be able to gain 10 pounds of muscle," he said. "Weight gain requires a long-term commitment."

The battle hardgainers face is winnable only if they set realistic goals, dietitians say. That means a gain of a half-pound to a pound a week or an extra 500 to 1,000 daily calories. More than that, the medical experts say, will only pack on fat. (Mr. Johnson, who was gaining about 2.6 pounds a week, admits to some flab.)

"You can only fool genetics so much," said Dr. William Roberts, a sports medicine specialist at the University of Minnesota. "It's still better to be on the lean side than the heavy side."

Angela Corcoran, a personal trainer at Equinox Fitness in Manhattan, recommends limiting cardiovascular activity in favor of weight lifting to the point where it is impossible to hoist any more. Ms. Corcoran also suggests devoting one workout a week to "negative" training in which, instead of bench-pressing a barbell, you concentrate on lowering it to the chest.

One of her clients, Antony Smithie, 37, an investment banker in New York, tried for years to add muscle to his 6-foot-2, 166-pound frame with standard gym circuit-training. Since he started working with Ms. Corcoran in September, he has gained 12 pounds and three inches around his chest.

Hank Drought, a personal trainer in Madison, Conn., said lifting heavy weights for 8 to 15 repetitions is a more effective way to put on muscle than working to failure. "Gaining muscle mass is like bodybuilding, not power lifting," he said. "They want to increase their size, not their strength."

Other trainers are concerned that the lift-heavy approach fails to take into account the long limbs of some hardgainers. Michael Mejia, the other author of "Scrawny to Brawny" and a personal trainer in Plainview, N.Y., teaches his clients to modify standard weight-lifting exercises.

"The guy with arms like an orangutan is going to have a lot of work to do on the bench press," said Mr. Mejia, who places a rolled-up towel on the rib cage to shorten the range of motion.

No matter how much time hardgainers put in at the gym, taking in calories is crucial in building body mass. Christopher Taylor, 42, an actor in Los Angeles, was tired of being cast as a deathbed patient. He consulted sports nutrition books and, another Anthony Ellis Web site, and put on 20 pounds. But then, after neglecting to keep up his food intake for six months, he lost almost all of it.

"Eating when you're full is gross," Mr. Taylor said. "It's definitely work to keep chewing."