Sam Kass, executive director of the Let’s Move initiative and the White House senior policy adviser for nutrition policy, inspects vegetables at the White House garden. (Bonnie Jo Mount/Washington Post)

Each president and first lady sets a new tone for the White House, partly based on personal beliefs and private quirks, but few have so transformed the culture inside the building the way the Obamas have regarding nutrition and fitness.

Gone are Tex-Mex Thursdays at the White House Mess and the least healthy vending machine options; calorie counts and hummus with vegetables are in. Working out with the Obamas’ personal trainer is one of the few acceptable excuses for being late to a meeting; the first family reserves desserts for weekend meals despite having a full-time pastry chef.

Earlier this year, there was an intense battle for bragging rights inside the complex as teams of six with names such as “Runnin’ Like Amtrak,” from Vice President Biden’s staff, and “Team Engage (Our Core),” from the Office of Public Engagement, earned a point for every 30 minutes of “moderate-to-vigorous physical activity” performed each day. Each team totaled its points each week.

“The culture here has shifted pretty dramatically, in direct ways and indirect ways, based on their leadership,” said Sam Kass, executive director of first lady Michelle Obama’s Let’s Move initiative and the White House senior policy adviser for nutrition policy. “I think we really live that. I think that’s been a transformation for the kitchen.”

There are large bowls of apples in the Oval Office and the first lady’s office, so aides can snack on them during meetings. The Obamas’ personal trainer, Cornell McClellan, offers his services to staff members as well.

President Obama and the first lady have made it clear they want staff members to take care of their health, especially after a couple of them had scares last year.

White House senior adviser Dan Pfeiffer had to reassess his work-life balance when he was hospitalized twice last fall, once after returning to the office the day after checking out. When the president and others gently chastised him for working too hard, Pfeiffer recalled thinking, “Okay, maybe that’s a good point.”

Obama has urged some of his aides in the past, such as Pete Rouse and David Axelrod, to train with McClellan to get in shape. “He’s somebody who’s going to encourage people, let’s put it that way,” said one former senior administration official.

And the president is not against poking fun at some of his male — but not female — staff members. Former chief White House speechwriter Jon Favreau recalled exercising with Obama in a hotel gym one morning during the 2012 campaign. The commander in chief praised him for working out but said: “Man, though, you’ve got skinny legs. You need to work on that.” Obama noted a moment later, “I’ve got the same problem.”

In Obamaworld, the methods staff members use to reach their diet and fitness goals reflect their faith in the power of technology and data. Council of Economic Advisers Chairman Jason Furman, who got kudos from the president after he lost 50 pounds, surveyed the scientific literature on weight loss, tracked his food consumption and rate of physical behavior electronically and converted it into a spreadsheet to analyze it properly.

“At first, I followed a daily budget,” he said. “But based on behavioral economics, I allowed myself to make exceptions — but only if I decided on it several days in advance — because we know that the discount rates we use for our future selves are lower so that we can make better trade-offs between immediate gratification and future costs. Making immediate decisions is myopic and liable to lead to systematically bad choices at the expense of our future selves.”

Peter Velz, a White House press assistant who belongs to a team of staff members that is halfway through a group fitness challenge, enters his gym time and other physical activities into “a shared Outlook calendar to keep track of everything.” Velz, who ran his first marathon four days before starting at the White House as an intern in 2012, said his colleagues’ commitment to working out underscores the fact they are “competitive people” who are intense about everything they undertake.

Traditionally, the workplace environment at the White House has not been a particularly healthy one; the schedule is so unrelenting that staff members have little time to exercise or prepare meals at home.

“You carve out time in the president’s schedule so he can be fresh, ready and available,” said Gordon Johndroe, who served as deputy White House press secretary under George W. Bush. That often means staff members “don’t necessarily have the time carved out for ourselves,” he said. “I can just think of a handful of times where we could take time to work out.”

Or as Brian V. McCormack, who served as Vice President Dick Cheney’s personal aide, put it: “I probably had more fried chicken tenders [in the White House Mess] than I’ve had in my entire life. The food is a matter of convenience, and you wanted to grab things and get back to work.”

Needless to say, the cultural shift has political consequences. For conservatives, it affirms their conspiracy theories about the trans fat-eschewing, honeycomb-tending, Let’s Move-loving White House.

Former Alaska governor Sarah Palin (R) made s’mores during a 2010 episode of her reality TV show and quipped it was “in honor of Michelle Obama, who said the other day we should not have dessert.” Conservative personality Glenn Beck declared at a Right Nation conference that year: “Get away from my french fries, Mrs. Obama! First politician that comes up to me with a carrot stick, I’ve got a place for it. And it’s not in my tummy.”

Previous presidencies were better known for their food indulgences. George H.W. Bush set off a firestorm not just by declaring he was “not going to eat any more broccoli” as president of the United States but by boosting the sale of pork rinds by declaring his affection for them. Bill Clinton would stop by a McDonald’s during his regular jogs, and even the physically fit George W. Bush relished ballpark food such as hot dogs for his dinner.

Republicans often frame the issue as a right to eat calorie-laden food as a question of individual liberty, although several of the initiatives the first lady has championed are voluntary. Others are not. The Agriculture Department has moved ahead with a suite of rules changing the way Americans eat: overhauling nutrition labels to put an emphasis on calories and sugar, raising the nutritional standards for school lunches and banning the marketing and sale of unhealthy foods and beverages in school cafeterias, vending machines or at bake sale fundraisers that occur during school hours.

“We’ll see some grumbling from high-school students this fall, but for a 5- or 6-year old, this will just be all they’ll ever know,” Kass said of the move to jettison junk food from vending machines.

Cultural and political factors drive the kind of food available in the White House. James Pinkerton, who served under Ronald Reagan and George H.W. Bush, defended Bush’s less-healthy eating habits: “People are definitely looking for relief from the masochism of the fitness craze. And if the president will let them off the hook and let them become kinder, gentler and flabbier, we’ll all be grateful.”

When Jimmy Carter was running for reelection in 1980, according to then-White House assistant pastry chef Ann Amernick, she and the head party chef baked “thousands of petit fours a day” for official parties.

Amernick, who now teaches baking classes in Baltimore, said they focused on producing classic French pastry. “We were doing everything with butter, eggs, sugar, chocolate and fruits — fresh fruits,” she said.

Frank Ruta, whose 11-year tenure as assistant chef at the White House spanned the Carter, Reagan and George H.W. Bush administrations, said the kitchen served the president’s family “three square meals a day” with dessert at lunch and dinner “to finish the meal on a sweet note. It didn’t have to be 500 calories.”

Ruta, who is now executive chef and owner of the D.C. restaurant Palena, fixed pimento cheese sandwiches for Amy Carter as well as fried chicken for her parents. Nancy Reagan liked to start her lunch with a consomme and have calf’s liver when her husband was out of town, because he wouldn’t eat it. (Ronald Reagan enjoyed hamburger soup when his spouse was on the road.) And Ruta noted that the Carters and Reagans were “budget-conscious” and used leftovers — every first family must reimburse taxpayers for the cost of their food.

The Obamas have emphasized local foods and exercise from the outset. Rick Bayless, who has cooked for them at his Chicago restaurant Topolobampo and at the 2010 state dinner for Mexican President Felipe Calderón, called them “joyful eaters, adventurous eaters — they eat for both pleasure and sustenance.”

In 2009, the first lady reestablished the White House kitchen garden, which has grown to encompass 1,900 square feet of prime South Lawn real estate and provides ingredients for the first family’s meals as well as state dinners. As of this year, it includes a pollinators’ garden, to emphasize the recent sharp decline in bees and butterflies’ populations.

National Gardening Association President Michael Metallo said his group found the rate of gardening among millennials has risen 63 percent in the past five years, and one in three U.S. households now has a food garden. “I don’t think you can look at that 63 percent and not think their message is getting through.”

The push is also credited with helping shift public attitudes about eating and contributing to the 43 percent decline in obesity rates among children ages 2 to 5 over the past decade.

There are limits to the Obamas’ influence. Only 10 percent of American gardeners plant kale, according to the NGA survey, even though the White House garden features three varieties of it this year.

“It’s still got a little ways to go,” Metallo said, diplomatically.