In the 2006 Krystal Square Off, Kobayashi's mark of 97 hamburgers was 30 better than his winning total in 2005 and 28 better than the World Record he set in 2004.
At a speed-eating contest in Hong Kong on August 13, 2005, Kobayashi consumed 83 vegetarian jiaozi dumplings in 8 minutes. The next day, he ate 100 roasted pork buns in 12 minutes. Kobayashi also won the 2005 Alka-Seltzer US Open of Competitive Eating, a three-hour IFOCE elimination tournament on ESPN, as well as the Glutton Bowl, a two-hour IFOCE eating special that aired on the Fox Network in 2002. However, on Fox's 2003 show Man vs. Beast, Kobayashi lost in an eating competition against a 1089-pound Kodiak bear, when he ate 31 bunless hot dogs in 2 minutes and 36 seconds to the bear's 50.
On August 5, 2006, Kobayashi set yet another world record at the Johnsonville World Bratwurst Eating Championship in Sheboygan, Wisconsin, by downing 58 bratwurst sausages in 10 minutes, shattering the previous record of 35 set the previous year by Sonya Thomas.
On September 23, 2006, Takeru Kobayashi set the world record at the Phantom Food Festival in Boston, MA for eating 41 Summer Shack Lobster Rolls in 10 minutes, replacing the previous record of 22 rolls.
Other world-eating records held by Kobayashi include 17.7 pounds of cow brains in 15 minutes and 20 pounds (9 kg) of rice balls in 30 minutes.
On June 25, 2007 Kobayashi announced on his blog that he seriously injured his jaw during training. He stated that he can only open his jaw about the width of a fingertip. Kobayashi's participation in the July 4, 2007 Nathan's contest continued as scheduled. He was able to eat a personal record 63 hot dogs, though his mark was bettered by Joey Chestnut who ate 66.
On July 4, 2008 he once again competed in the Nathan's contest. He and Joey Chestnut reached a tie of 59 hot dogs and buns each, but came in second to Chestnut in a 5-dog tiebreaker eatoff. Chestnut won the 92nd Annual Nathan's Hot Dog Eating Contest at Coney Island, Brooklyn, N.Y., by eating 66 hot dogs and buns in 12 minutes. Chestnut, 24, weighed in at 102 kilograms (225 pounds).
Physically Kobayashi has undergone drastic change from his earlier appearances on the competitive eating circuit, weighing in at a mere 110 lb (50 kg) in his beginning competitions and then 144 lb (65 kg) in later events. This is due in large part to his more recent endeavors in weight training. By training with weights and working out, Kobayashi has increased his metabolism, which in turn has helped him to burn more calories. This training is used by Kobayashi to maintain his overall health as well as helping him to prevent excess calories from being stored as fat.
Kobayashi's official Web site gives his height as 173 cm (5 ft 8 in) and his weight as 75 kg (165 lb), but in a June 29, 2006, entry on his blog, he says that his weight grew to over 87 kg (191.8 lb) during 2006, still being under 10 percent body fat. Kobayashi has said in recent years that he consumes an average of 6,000 calories per day. As of July 3, 2008, Kobayashi's had dropped to 128 lbs, as recorded at the weigh in for the annual Fourth of July hot dog eating competition on Coney Island. This is the same weight he'd originally competed at when he first began competitive eating in the United States. Kobayashi is also known for his trademark body wiggle, referred to by some as the "Kobayashi Shake", to force food down his esophagus and settle more compactly in his stomach. He eats the hot dogs by splitting the frankfurter in half, swallowing both parts at once, and then dipping the buns in water, Sprite, or 7-Up and stuffing it in his mouth. He calls this the Solomon method.
Kobayashi was the Nathan's Hot Dog Eating Contest winner for an unprecedented six years in a row. He was the world champion in that competition until 2007, when he finished in second place behind winner Joey Chestnut.
*Lost 5 hot dog eat-off. Match was also 10 minutes instead of 12 minutes.