| variation of hydrogen, carbon, nitrogen, and oxygen stable isotope ratios in an american diet: fast food meals. | the stable isotopes of hydrogen, carbon, nitrogen, and oxygen provide insights into a heterotrophic organism's diet and geographic origin. although the contribution of food delta (2)h and delta (18)o to the final tissue signal will not vary for constrained diets, it will for animals eating varied diets, that is, humans. this study surveyed the isotopic range in one portion of the american diet, fast food meals. hamburger patties, buns, and french fries from national chain restaurants across the ... | 2008 | 18481865 |