US habits leave migrants with a lot on their plate Health fears: Esther Angeles, 41, who developed diabetes after moving to the US, eats lunch with her daughter. Becoming an American can be bad for your health. A growing body of mortality research on immigrants has shown that the longer they live in the US, the worse their rates of heart disease, high blood pressure and diabetes. And while their American-born children may have more money, they tend to live shorter lives than the parents. The pattern goes against any notion that moving to America improves every aspect of life. It also demonstrates that, at least in terms of health, worries about assimilation for the country's 11 million illegal immigrants are mistaken. In fact, it is happening all too quickly. "There's something about life in the US that is not conducive to good health across generations," said Robert Hummer, a social demographer at the University of Texas in Austin. For Hispanics, the nation's largest immigrant group, the foreign-born live about three years longer than their American-born counterparts, studies have found. Why does life in the US - despite its sophisticated healthcare system and high wages - lead to worse health? New research is showing that the immigrant advantage wears off with the adoption of American behaviours - smoking, drinking, high-calorie diets and sedentary lifestyles. In Brownsville, a worn border city studded with fast-food restaurants, immigrants say that happens slowly. In the US, foods such as ham and bread are sweetened. And children lose their taste for traditional Mexican foods. For the recently arrived, the quantity and accessibility of food speaks to the boundless promise of the US. Esther Angeles remembers being amazed at the size of hamburgers - as big as dinner plates - when she first came to the US from Mexico 15 years ago. "I thought, this is really a country of opportunity," she said. Look at the size of the food! "We have a time bomb that's going to go off," said Amelie Ramirez, a professor of epidemiology and biostatistics at the University of Texas health science centre in San Antonio. Obesity rates are increasing. Diabetes is exploding. The cultural protection Hispanics had is being eroded.