McDonald’s on Thursday reported surprisingly upbeat quarterly earnings and revenue, but CEO Chris Kempczinski — who recently went viral for his weirdly timid nibble of his own company’s burger — warned consumer spending may get “a little bit worse” as high fuel prices slam wallets. The fast-food chain saw adjusted earnings per share of $2.38 in its first quarter – beating expectations of $2.74. It also raked in revenue of $6.52 billion, above estimates of $6.47 billion. McDonald’s said its same-store sales rose 3.8% in the first quarter. In the US, same-store sales jumped 3.9% as customers spent big at the Golden Arches when they visited. McDonald’s CEO Chris Kempczinski warned that consumer spending may get “a little bit worse.” REUTERS Shares in McDonald’s jumped 0.6% Thursday morning. But analysts have warned that fast-food chains will likely see low-income consumers flee as the Iran war drives gasoline prices higher, taking a bite out of Americans’ savings.…