1 . 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.

2 .                                                                                      You May Need a Few Minutes of Brisk Activity

Walking from room to room, running up and down stairs to deliver folded laundry, or taking a jog around the block... Which ones would best help or hurt your brain? A recent study attempted to a answer that question by strapping( 绑上) activity monitors to the thighs of nearly 4,500 people in the United Kingdom and ________ their 24-hour movements for seven days. Researchers then examined how participants’ behavior affected their short-term memory, problem-solving and processing skills.

Here’s the good news. People who spent “even small amounts of time in more vigorous activities—as little as six to nine minutes—compared to sitting, sleeping or gentle activities had ________ cognition scores,” said study author John Mitchell.

Moderate physical activity is ________ defined as brisk walking or bicycling or running up and down stairs. Vigorous movement ________ dancing, jogging, running, swimming to biking up a hill—basically any activity that is able to ________ your heart rate and breathing.

The study found that doing just under 10 minutes of moderate to vigorous physical activity (MVPA) each day led to ________ in study participants’ working memory. In addition, 10 minutes of MVPA had its biggest impact on executive processes such as ________and organization.

The cognitive improvement was ________, but the research found that the benefits grew the more time a person spent ________in the activity of an energetic workout, Mitchell said.

“Now that we don’t monitor participants’ cognition over the course of many years, the results of this study may simply be telling us that those individuals who move more tend to have higher cognition on average,” he said. “While on the other hand, the results do also imply that even making ________ changes to our daily lives can have ________ consequences for our cognition.”

There was bad news as well. Spending more time sleeping, sitting or engaged only in mild movement was linked to a negative impact on the brain. The study found cognition declined 1% to 2% after replacing an ________ portion of MVPA with eight minutes of sedentary (久坐的) behavior, six minutes of light intensity or seven minutes of sleep.

Additional studies need to be done to ________ these findings and to better understand the role that each type of activity plays ________ our cognitive abilities. However, Mitchell said, the study “highlights how even very modest differences in people’s daily movements— less than 10 minutes— can be linked to the ________of quite real changes to our cognitive health.”

3 . Better grades might be found on the playground. A new study of elementary-age children shows that those who were not part of an after-school exercise program tended to pack on a particular type of body fat that can have deleterious impacts on brain health and thinking. But prevention and treatment could be as simple as playing more games of tag (捉迷藏，捉人游戏).

Most children do not meet the federal health guidelines for exercise, which call for at least an hour of it a day for anyone under the age of 18. Physical inactivity can result in weight gain especially around the midsection-including visceral (内脏的) fat, a type of tissue deep inside the abdomen (腹部) that is known to increase inflammation (炎症) throughout the body. It is also linked to heightened risks for diabetes and cardiovascular complications (并发症) even in children, and may contribute to declining brain function. Obese adults often perform worse than people of normal weight on tests of thinking skills.

But little has been known about visceral fat and brain health in children. For a soon-to-be-published study, researchers from Northeastern University in Boston and the University of Illinois at Urbana-Champaion tracked hundreds of 8-to-10-year-old children in a nine-month after-school exercise program in Urbana. Every day, one group of children played tag and other active games for about 70 minutes. The subjects in a control group continued with their normal lives, with the promise that they could join the program the following year. All the children completed tests of fitness, body composition and cognitive skills at the start and end of the program. The researchers did not ask the children to change their diets.

After the trial the exercising children who were obese at the study’s onset had less visceral fat relative to their starting weight, even if they remained overweight. They also showed significant improvements in their scores on a computerized test that measures how well children pay attention, process information and avoid being impulsive. Notably a similar effect was observed in children whose weight was normal at the start. Across the board the more visceral fat a child shed during the nine months of play, the better he or she performed on the test.

The children in the control group, in contrast had generally added to their visceral fat; this was particularly true among those who were already obese. They gained on average, four times as much visceral fat as the normal-weight children in the control group, and also did not perform as well on the subsequent test. Lauren Raine, a postdoctoral researcher at Northeastern University who conducted the study with Charles Hillman and others, says that the trial was designed to study aerobic fitness and children’s ability to think not the relation of abdominal flab to inflammation. But a reduction in overall inflammation very likely plays a role because it is thought to be unhealthy for the brain. More broadly, Raine says the study suggests that getting children to run around won’t just enhance their bodies-it might also improve their report cards.