Being tired is linked to something deeper than just overwork or a sign of the times. I'm a registered dietitian and nutritional neuroscientist. My research, along with the work of others in the field, shows that your diet and lifestyle choices may contribute to your struggles. These two factors are closely interconnected and could be the key to understanding what's holding you back. Foods high in vitamin D include fatty fish like salmon, sardines, freshwater rainbow trout, fortified dairy products and egg yolks. Among the sources for vegetarians and vegans are fortified plant-based milks and cereals and some kinds of mushrooms. The U.S. government's recommended daily amount of vitamin D is 400 international units, or IU, for infants up to 12 months, 600 IU for people ages 1 to 70 and 800 IU for people over 70. Just over 5 ounces (150 grams) of sockeye salmon fillet has about 800 IU of vitamin D. If you are low in a vitamin, your doctor may prescribe you a higher dose than the recommended daily amount to elevate your blood levels to normal....

Macros seem to come up often in the corners of the internet and social media devoted to people trying to lose weight, improve their health, look better and feel better about themselves. But what the heck is a macro' With more information than ever available at your fingertips, and more diets out there than you have fingers and toes to count on, it's no wonder you might be confused. As an exercise science specialist interested in physical health and nutrition, I've got you covered. If you look at a nutrition label, you'll see that macros are measured in grams. But it's important to understand that the calories per gram for each macro aren't the same. Protein and carbohydrates each have 4 calories per gram, while fat has 9 calories per gram. In other words, fat provides more than twice the amount of energy per gram compared with protein and carbohydrates. People rarely eat proteins, carbohydrates or fats in isolation. For example, while chicken is widely considered a source of protein, it also contains fat. Almost every food contains more than one macronutrient....

The new year has begun, bringing with it the socially sanctioned push to make resolutions. Readers, or those who want to devote more time to reading, tend to set some quantifiable intentions for the year to come. A popular one is finishing an arbitrary number of books; another approach is to establish specific parameters'reading only titles by women for a year, meeting a quota for books in translation, or trying one work from every country. Some readers opt for one or two giant books that are notoriously demanding. There's nothing wrong with these aspirations, but personally, I'm a bit allergic to this kind of goal setting. I don't like hemming myself in with strict rules'and I don't want to let my inner perfectionist force me to continue a challenge long after I've stopped enjoying it. More important, strict directives prioritize box-checking over holistic growth. There are many ways to advance your skill and capacity as a reader: Some of us are naturally drawn to detailed nonfiction, and others must learn to love it; some may have a taste for meandering, multigenerational epics, while their friends must train to build up the attention span they need. Depending on your particular strengths and desires for change, a single book may offer a better workout than a dozen others combined. Each of the five books below exercises a different kind of reading muscle, so that you can choose the one that will push you most....

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....