5 . One of the presents in my house this Christmas was a late 18th-century volume of the Encyclopaedia Britannica (大英百科全书). It is a window into the discoveries and thinking of the time. The encyclopaedia is an entertaining reminder of how _______ some of our current truths are bound to be. Certainties in areas we haven’t yet understood will look just as ridiculous as some of these in centuries to come. And one of those we are still remarkably _______ is the effect of food and exercise on our bodies. We’re surrounded by confident _______ on how to eat, how to avoid or reverse obesity (肥胖), and yet the advice seems pointless while the world gets fatter. Much of what we think we know is a pile of assumptions rather than _______ .

Our confusion is the theme of Spoon-Fed, a book by one of Britain’s leading nutrition researchers, Tim Spector of King’s College London. Its subtitle is: “Why almost everything we’ve been told about food is wrong.” It is a call for us to _______ more.

One by one Spector offers answers to recent food _______. Coffee can save our lives, he says. Three to four cups a day reduces the risk of heart disease and may cut the risk of death by 8 per cent. Butter does not damage our hearts, Spector argues, and salt is vital. Eggs have gone “from heroes to villains and back again”. Don’t say no to all red meat on _______ grounds; occasional small quantities of high-quality unprocessed meat provide important vitamins and iron and are “probably good for you“. Exercise is so good for longevity and happiness that it should be considered our No 1 drug, but the one thing for which it’s _______ useless is losing weight. Vitamin pills are a multibillion-pound industry with almost no proven _______ but which can cause real harm. Even vitamin D, which Spector used to study and believe in, he now _______.

Spector also offers more than a set of currently _______ tips. The science of nutrition has not been solved by him, as he would be the first to admit. His most _______ point is that there is no one size that fits all. Our bodies are complex, and our reactions are _______: yet nobody wants to pay for the research that might explain why.

Some combination of food choices, genes, environment and the chemical reactions generated by our microbiome — the unique microbe (微生物的) combinations in our body ― yes different _______ for each of us, leaving some lean and two thirds of us too fat. This is the territory Spector wants to explore further and which might just allow us to _______ the global trend to obesity, with all the risks we’ve witnessed this year.

9 .

10 . Winter is a great time to experiment with new sports. The key is to find one that matches your interests and natural abilities. If you like to walk, keep walking—on snowshoes. If you want to try an endurance sport, go for cross-country skiing. Besides, snowboarding is just great fun.

Not satisfied with these? Try downhill skiing, then. Downhill skiing is not as hard as it used to be—shorter, lightweight, curved skis make any beginner feel like an Olympic winner. These newer skis—along with another type of equipment called ski boards, which are even shorter than skis—help you control your speed and body movements.

Consider testing the latest high-tech skis or snowboards? Check with your local sports shops or the rental places at the ski mountains about sample programmes.

You could also try sledding. Use a wood-framed sled with steel runners or a plastic sled to head down a snowy hill. If you prefer ice to snow, think hockey or figure skating.

Runners can also train during the winter in spite of wet or slippery roads. One of the easiest sports around, snowshoeing can be excellent cold-weather cross-training for runners and cyclists—or anyone wanting to take a wintry walk in the woods. Snowshoes are smaller, lighter, and better than ever. If you want to try them out, you may be able to rent a pair for a day at many of the larger outdoor or sporting goods stores.

Whatever sport you choose, don’t rely on a friend for instruction. You wouldn’t let an inexperienced doctor perform a brain operation on you, but why let one teach you to ski or skate? That’s what instructors are for—to help newcomers start out right. Instructors can give you advice about equipment, techniques, safety, and dealing with injuries if they do happen to you.

Above all, if you want to progress, invest your time in learning the basic skills thoroughly. Everything else you do as a skier, boarder, or skater will be built on these first skills.