When Dr. Dean Schillinger started his residency at San Francisco General Hospital in 1991, practically every other patient he saw had AIDS. Now just about every other patient has diabetes.

Forty percent of the general medicine practitioner’s patients have diabetes, and an additional 25 percent have prediabetes. But unlike the city’s battle against AIDS, there aren’t big rallies in the streets demanding more funding for diabetes research. Nobody, according to Schillinger, really cares.

“The AIDS ward is now full of (diabetic) amputees and kidney failure. ... It was hell on earth back then, and it still is,” said Schillinger, 50. “I like to say we’re in a public health war on the home front that nobody’s really talking about.

“Now there’s nobody protesting, because it’s all black and Latino people, and Asian immigrants,” said Schillinger, who specializes in research about how poverty contributes to diabetes. “Who cares about them?”

Schillinger cares about them. And his provocative, direct words make him stand out in San Francisco’s continuing political battle over whether to tax soda and other sugary beverages to try to curb diabetes, obesity and tooth decay. After failing in 2014, a soda tax will be back on the ballot in November, and a morning at the hospital with Schillinger demonstrates why he’s such a believer.

As a professor of medicine and chief of the UCSF Division of General Internal Medicine, Schillinger spends most of his time writing grants and performing research. Ten years ago, he founded the UCSF Center for Vulnerable Populations at S.F. General, which researches chronic diseases in poor communities. But despite his workload, Schillinger spends every Monday in the hospital’s Richard Fine Clinic providing primary care to patients.

Patient’s view of soda

On a recent morning, one of those patients was 66-year-old Bayview resident Ruth Arrozco. Like most of Schillinger’s patients, diabetes is just one of her many diagnoses — she also has pancreatitis, kidney stones and depression.

Arrozco said she used to drink a couple of sodas a day, but has cut back to one a week. She said she thinks soda contributed to her getting Type 2 diabetes and supports a tax on it.

“So people wouldn’t buy it,” she said matter-of-factly. “If someone sees it on sale, they want to get it, just like cigarettes and alcohol.”

Another patient, Mary Lourent, is 81 and lives in the Ingleside district. She’s one of the rare patients whose diabetes is so well under control, she’s been able to reduce her medication dosage and hardly shows any signs of the disease. “This is a doctor’s dream,” Schillinger said.

Still, he sees her regularly as he has since he started at the hospital 25 years ago. As with every patient, he examines the skin between her toes to ensure there’s no fungus; people with diabetes sometimes can’t feel their feet and don’t notice infections before it’s too late.

Lourent said she used to drink soda and eat a lot of sugary food — that’s just the way it was in her family. Her sisters both have diabetes, and a cousin’s legs were amputated because of the disease. (Schillinger uses this anecdote to segue into the statistic that during the 10 years of war in Iraq and Afghanistan, 1,500 American soldiers lost limbs — and during that same time, 730,000 Americans lost limbs to diabetes.)

48% of adults in S.F.

Schillinger has long, wavy dark hair and wears the sport jacket and colorful button-down shirts of an English professor. While he loves treating patients, he also loves talking about the latest research about diabetes, a disease that has captured his attention because it went “from rare to commonplace right in front of my eyes.”

Recent UCLA research, for example, found that 55 percent of adults in California have been diagnosed with diabetes or prediabetes or have the disease but are undiagnosed. In San Francisco, that number is 48 percent.

Schillinger’s research has concentrated on proving the link between diabetes and food insecurity — or being so poor that you regularly don’t have enough food. The disease is more common in poor communities than wealthy ones.

Pattern of hospitalization

Schillinger’s protege, Hilary Seligman, recently expanded on his research to prove that low-income diabetes patients are hospitalized more at the end of the month than at the beginning. That’s because their money runs out, so they’re taking their diabetes medication while not eating enough, leading to low blood sugar and even coma. This phenomena doesn’t happen as much in November and December because food programs offer so many free meals around Thanksgiving and Christmas.

These kind of findings have spurred Schillinger to support taxing soda. In 2014, city voters narrowly defeated a ballot measure that would have added a 2-cents-per-ounce tax to the sales of soda and other sugary drinks.

While Schillinger was out front on the pro-tax campaign — visiting newspaper editorial boards, writing opinion pieces and speaking out at public meetings — most of his UCSF colleagues remained quiet. Schillinger said there was a “perceived restriction” at the university about speaking in favor of the soda tax.

“If we had the full force of UCSF behind this, the outcome could have been different,” he said.

Mayor Ed Lee and the city’s Department of Public Health also did not take sides.

The tax will appear again on the November ballot, but this time at just 1cent per ounce. Unlike in 2014, when the tax measure needed two-thirds of votes to pass, this time it needs a simple majority because it doesn’t earmark the tax money for any special purpose. Last time around, the money was to be dedicated to physical education and nutrition programs for children.

Impact on poor

Schillinger is hopeful San Franciscans will back the tax this time, and he remains unafraid to challenge anybody who opposes it. Lee, notably, is backing the tax this time around.

A big knock on the tax last time was that it would make life even more expensive for low-income people in an already pricey city. Schillinger scoffs at that concern, saying if it spurs people to buy less soda, it’s worth it.

“OK, it’s a regressive tax,” he said. “But they’re paying such a heavy price every single day with their diabetes. Compared to a penny per ounce for a soda, the human cost is incalculable.”

Industry feels singled out

While passage of the soda tax appears more likely in November than in 2014, it’s not a given. The beverage industry spent about $10 million to defeat the tax last time and is expected to fight the new effort.

Roger Salazar, a spokesman for the California Beverage Association, which opposes soda taxes, said blaming one product for the increase in diabetes and obesity simplifies the issue.

“Not only do you need to look at all other foods, you need to look at lifestyle and exercise,” he said. “There are many, many factors that go into these diseases. To single out one particular product undermines how complex these diseases really are.”

Schillinger in February was one of six Californians awarded the James Irvine Leadership Award, which recognizes people who find effective solutions to major state problems. He was honored for co-founding the Bigger Picture campaign with Youth Speaks that pairs teens from low-income families with mentors to write poetry about diabetes from the social justice perspective.

Schillinger lives in the Richmond District with his wife, Ariella Hyman, who is a managing attorney in the Alameda County office of Bay Area Legal Aid. (“It’s like the S.F. General of the law,” Schillinger quipped.) They have 17-year-old twin boys and a 9-year-old daughter. The kids are not allowed to have sugary drinks at dinner, and Schillinger hardly consumes any sugar himself. He did allow his daughter to roast three marshmallows on a recent camping trip, however.

Schillinger grew up in Buffalo, N.Y., the son of a teacher mom and surgeon dad. He attended Brown University as an undergraduate, studying Russian language and literature, and University of Pennsylvania for medical school. In 1991, he moved to California for a residency at S.F. General and has worked there ever since.

“This is a miraculous place,” he said, saying it’s rewarding to treat patients who are in such need of his care. “It’s inspiring to be their doctor.”

One of his final patients of the day was Valentina Nikitskaya, an immigrant from Russia who speaks only Russian, a language Schillinger knows, along with Spanish. Still, he used an interpreter on a conference call to ensure that he caught every word.

Nikitskaya is 65 and lives in a little Mid-Market apartment. Her diabetes is not well-controlled, and Schillinger prescribed a higher dosage of medication. She also said she can’t afford new diabetic shoes, constructed to reduce skin breakdown.

“Can you prescribe me some?” she asked.

Schillinger called one of the hospital’s social workers into the room to help Nikitskaya get new shoes. But he had a bigger question on his mind.

“You said you don’t have enough money for shoes,” he told his patient. “Do you have enough money for healthy food? Not having the best food can make your diabetes worse.”

‘Stay healthy’

The social worker also gave Nikitskaya a list of food pantries in the city, and Schillinger told her to prioritize fresh fruit and vegetables over boxed or canned food.

The patient said she doesn’t drink soda — she actually thinks it should be banned — but she confessed a weakness for one tablespoon of honey a day. “I can’t live without honey,” she said, looking anxious.

“Enjoy it!” replied Schillinger, who believes moderation is key. “Enjoy it, sweetheart.”

Armed with a new prescription and leads on diabetic shoes and healthy food, Nikitskaya thanked the doctor and collected her things.

“Stay healthy,” she told him. “Don’t ever get sick.”

Heather Knight is a San Francisco Chronicle staff writer. Email: hknight@sfchronicle.com Twitter: @hknightsf