WASHINGTON - A venerable fixture of the US capital is offering visitors a peek at presidential recipes including Lyndon B. Johnson's Texas chili, John F. Kennedy's Cape Cod chowder and Dwight D. Eisenhower's three-page guide to vegetable soup.

The National Archives opens its first exhibit Friday on the history of US food and the government's effect on the nation's diet. "What's Cooking Uncle Sam?" is a departure for the Archives, which more often deals with issues of presidential policies, war and peace.

Former White House executive pastry chef Roland Mesnier, who served Presidents Jimmy Carter through George W. Bush, said the government also has a critical role in setting the nation's food agenda. Making the healthiest food more affordable would be an important step, he said.

Mesnier said he was hired at the White House because he promised first lady Rosalynn Carter he would make healthy, light desserts with lots of fresh fruit.

Some presidents, though, did not always follow Mesnier's advice. The chef recalled making special desserts for President Bill Clinton, who was allergic to dairy products, chocolate and flour.

"Mr. President, I have your special cake here," Mesnier would tell Clinton.

"Oh, no, no, I want a piece of that cake," Clinton fired back, pointing to a chocolate slice. "I am the president of the United States, so pass it on."

"I knew every time that he had been a bad boy because he would get a lot of pockets under his eyes," Mesnier said.

Beyond presidential menus and Queen Elizabeth's recipe for scones sent to Eisenhower, curators looked back at the history of farming, food processing, nutrition guidelines and the effects of military food and school lunches.

The exhibit includes the story of explorers sent around the world by the US Agriculture Department in the late 1800s and early 1900s to find seeds and plants to crossbreed and help American crops survive harsh climates. It also includes the push for safeguards in the Pure Food and Drug Act of 1906 and a letter from Upton Sinclair to President Theodore Roosevelt about the meatpacking industry.

The Archives holds a broad collection of posters showing the importance of food during World War II as the government promoted victory gardens and rationing of supplies.

"Know Your Onions," touts one poster. "Food is ammunition, don't waste it."

The exhibit includes more than 100 original documents and images, as well as government videos.

There is an amusing look at food marketing, including a company's pitch for branding "Vitamin Donuts," and many antiquated nutrition guidelines, well before the recently retired food guide pyramid and new "My Plate" guide introduced by the Obama administration.

A 1945 government poster includes "butter and fortified margarine" as one of seven basic food groups. The guide also called for eating "any other foods you want."