Desert Survivalist

 is an achievement in Fallout: New Vegas which is awarded for successfully healing 10,000 points of damage using food.

Food regeneration explained
(The previous was not correct)If consumed in one go with a minor amount of damage all points are added on to this achievement (check in Data, Misc and the Desert Survivalist if you don't believe me). This means that if your Max HP was 200 and you currently had 190 HP then eating food in one go (not leaving the pip boy) will add up and all count towards this achievement (must have a small amount of damage in first place even 1 HP). Which saves time from the drowning method.

The best way therefore to do this is to wait either at the food suppliers in the Ultra-Lux or Camp McCarran for 72 hours in between stocking up on food hurt yourself slightly or punch someone then after they hit you lower your arms so they stop (if good Rep) and then use them all.

Bottled water counts, however Nuka Cola, Sass and non bottled water do not.

One other thing to note, there seems to be a limit (4---a limitation of the Gamebryo engine dating back to Morrowind) to the amount of unique things that you can eat at once that actually take effect. After hitting that limit, you no longer gain stat adjustments/rads/FOD/points towards Desert Survivalist. If this occurs, simply wait until some of the food items "wear off," then continue consuming.

Locations for obtaining food, en masse

 * William Farber inside the Terminal Building at Camp McCarran stocks a large amount of vegetables and he restocks every 72 hours.
 * Make your way from Ruby Hill Mine to Jacobstown. You can encounter a lot of Bighorner bulls. Each will often     contain 3 to 5 Bighorner meat that restores 30HP (depending on your Survival skill).
 * Etienne at the Westside Co-op stocks a large amount of vegetables and other food.
 * You can find lots of Malnourished Bighorner and Malnourished Brahmin at Matthews Animal Husbandry Farm that won't attack you.
 * Genaro sells a variety of suspect meats inside Freeside's North Gate.
 * In the refrigerator inside the McBride house there are 10 Brahmin steaks. It's requires you to steal them unnless you have completed The Screams of Brahmin.
 * If you have the Followers Safehouse, you can get as much food as you need. The Followers of the Apocalypse doctor restocks the fridge while she's there, and as long as she's in the safehouse, the fridge is immediately restocked as you take from it.
 * The Presidential Suite in the Tops Casino is stocked with fresh fruit.
 * The Boomer Chef in the Mess Hall & Munitions Storage at Nellis Air Force Base usually have a wide variety of food.
 * The Ultra-Luxe sells Wasteland omelet. Resupplied every Sunday and Wednesday. Also, there are fresh vegetables and meat in the basement, but this requires stealing them.
 * Kill a bunch of Giant radscorpion in The Thorn or Scorpion Gulch, get a total of 150-200 Radscorpion poison gland, and bring them to Ruby Nash in Primm and tell her to make some of her famous casserole.
 * You can also get unlimited number of foods from Sierra Madre vending machine at Abandoned Brotherhood of Steel bunker, if you have Dead Money add-on.
 * There is also lots of food in the refrigerators in the Vault 3 cafeteria behind a locked door.
 * In caves around Zion Canyon you encounter large amounts of Cave Fungus (50+).