Robert F. Kennedy Jr. has some thoughts about Ozempic. According to the nominee to run the Department of Health and Human Services, the government should not provide the drug for millions of Americans, but instead address obesity and diabetes by handing out organic food and gym memberships. Like many of RFK's statements, these ideas have elicited some outrage. Their basic premise, though'that Americans should control their weight by eating better and getting exercise'could not be more mainstream. But this commonsense philosophy of losing weight, as espoused by RFK, the FDA, and really almost any doctor whom you might have asked at any time in recent memory, has lately fallen out of step with the scientific evidence. Lifestyle interventions have been central to the nation's decades-long attempt to curb its rates of chronic illness. Eat less, move more: This advice applies to almost everyone, but for those who have obesity or are overweight'about three-quarters of the adult population in the U.S.'dieting and exercise are understood to be among the most important methods to improve their health. Even now, when doctors have access to Ozempic and related GLP-1 medications, which deliver lasting weight loss and a host of life-extending benefits without the need for surgery, changes to behavior still take precedence. Formal treatment guidelines for obesity have affirmed RFK's approach, more or less, and argued that 'lifestyle therapy remains the cornerstone of treatment.' And according to the government, the drugs themselves are fit for use only 'as an adjunct' to a reduced-calorie diet and increased physical activity....

Reboot your immune system with intermittent fasting. Help your 'good' bacteria to thrive with a plant-based diet. Move over morning coffee: mushroom tea could bolster your anticancer defences. Claims such as these, linking health, diet and immunity, bombard supermarket shoppers and pervade the news. Beyond the headlines and product labels, the scientific foundations of many such claims are often based on limited evidence. That's partly because conducting rigorous studies to track what people eat and the impact of diet is a huge challenge . In addition, the relevance to human health of results from studies of animals and cells isn't clear and has sometimes been exaggerated for commercial gain, feeding scepticism in nutrition science. In the past five or so years, however, researchers have developed innovative approaches to nutrition immunology that are helping to close this credibility gap. Whereas nutrition scientists have conventionally studied the long-term impacts of loosely defined Mediterranean or Western diets, for example, today they have access to tools that allow them to zoom in on the short-term effects ' both helpful and harmful ' of narrower food groups and specific dietary components, and to probe the molecular mechanisms underpinning the effects of foods on immunity....

Ancient DNA confirms that the nineteenth-century carnivores hunted humans and a variety of wild game, including a surprising animal....

Giving male mice a high-fat diet raises levels of some types of RNA in their sperm, the study found. The research also showed that the male offspring of male mice on this unhealthy diet had metabolic problems such as glucose intolerance, a characteristic of diabetes. The sons of human dads with a high body mass index (BMI) exhibited similar problems, according to epidemiological analysis. Studies have shown that mothers can pass on metabolic traits to their offspring. As for fathers, Qi Chen, a reproductive-biology researcher at the University of Utah School of Medicine in Salt Lake City, and his team showed in 2016 that fertilized mouse eggs injected with sperm RNA from dads on a high-fat diet developed into mice with metabolic disorders2. Research shows that the ripple effects of a parent's diet are caused by changes not to the offspring's genome but to their 'epigenome' ' the collection of chemical tags hanging from DNA and its associated proteins. For the Nature study, male mice ate a high-fat diet for two weeks. The study's authors found that this regimen led to changes in a type of RNA in the sperm's mitochondria ' the structures inside cells that generate energy. The affected molecules, called transfer RNAs, are intermediate products in the process of transcribing DNA into proteins....