food and drug administration commissioner margaret hamburg announced thursday that she will step down next month after nearly six years overseeing the agency, which regulates products making up 25 percent of the u.s. economy. during her tenure the fda undertook major efforts to improve food safety, regulate tobacco and improve reviews of drugs. here&39s a look at some of those effortsfoodunder hamburg, the fda worked to implement sweeping food safety rules and proposed new nutritional information on food packaging and calorie information on restaurant menus.the agency also has given a definition to "gluten free" and taken a tough stand by pushing popular products that proved harmful off the market, like alcoholic energy drinks and caffeine gum.hamburg had the help of first lady michelle obama, who personally announced the efforts to revise the nutrition labels in an event at the white house last year. president barack obama pushed the food safety legislation, which congress passed in 2010, after a widespread salmonella outbreak in peanuts.the fda&39s food reforms have sometimes angered food companies and farmers, who have pushed back. the safety rules would give the government new powers to inspect processing plants, order recalls and impose stricter standards for imported foods. it also requires stricter food safety standards on farms and in manufacturing plants, with the idea of preventing illness before it occurs, rather than responding after people get sick.the rules mark the first time that fda has broadly regulated farms for food safety, requiring farm businesses to make sure workers&39 hands are washed, irrigation water is clean and that animals stay out of fields, among other things. the agriculture industry said the rules fda proposed in 2013 were too restrictive, so the agency revised them a year later.amid the industry pushback, some of hamburg&39s early goals have been delayed, including voluntary guidelines for reducing sodium in foods, calorie labels on the front of packages and guidance on labeling genetically modified foods.drugsas pharmaceutical manufacturing increasingly moved overseas, the fda under hamburg tried to step up oversight of plants in asia and other developing regions. before hamburg&39s arrival the agency was criticized for a spate of contamination problems with imported drugs, including a blood thinner from china linked to dozens of deaths and hundreds of allergic reactions. hamburg made highprofile trips to india and china to enlist the cooperation of foreign officials, while also expanding the agency&39s own staff in those countries.over the last six years, the pharmaceutical industry resumed its perennial criticism about the pace of drug reviews. but the agency has kept up with its commitments, reviewing most regular drugs in about a year and priority drugs in under seven months. hamburg highlighted the use of various programs to expedite approval of innovative drugs, including a "breakthrough therapies" program that has become popular with drug makers. 
