A U.S. registered dietitian suggests some foods might sound healthy but some so-called health foods are best avoided. Katherine Tallmadge, author of the book \"Diet Simple,\" told The Washington Post the U.S. Agriculture Department\'s Economic Research Service says the U.S. agricultural system produces twice the population\'s nutritional requirements and this encourages creative marketing to unload the excess, much of it with minimal nutritional value. Energy bars, or meal replacement bars, are marketed as a way to help lose weight and build muscle, but in reality can be candy bars with vitamins and added protein or fiber. Most have sugar as the first or second ingredient, Tallmadge said. Snacks labeled as baked, low fat or gluten-free are often made with refined grain or starch, which provide plenty of calories and few nutrients, Tallmadge added. She recommends avoiding reduced-fat peanut butter because the oil is the healthiest part of a nut, containing most of the nutrients, so there is no real advantage to taking it out of peanut butter. Walter Willett, a professor of epidemiology and nutrition at Harvard\'s School of Public Health, said drinks such as Vitaminwater are essentially sugary drinks with a vitamin pill and are \"unequivocally harmful to health.\" Some might be getting too much of some vitamins and minerals if they add vitamin water on top of fortified foods and supplements, Willett said.