It’s hard to say no to hamburgers, French fries and all of the other junk food. However, eating too much junk food can harm your body, especially if you’re between the ages of 10 and 19. “Junk food shapes teenage brains in ways that harm their ability to think, learn and remember. It can also make it harder to control impulsive (冲动的 ) behaviors,” said Amy Reichelt, at Western University, Canada. “It may even raise a teen’s risk of mental (精神上的) problems.”
Reichelt and two other researchers reviewed more than 100 studies, about how poor food choices can affect teenage brains. They found teenagers are more sensitive (敏感的) than any other age group to foods with a lot of fat and sugar as their brains are not yet fully formed.
Teenage brains are still developing the ability to notice risks and control actions. The prefrontal cortex (前额皮质) is the part of the brain that tells us we shouldn’t eat chips all the time and helps us control ourselves. However, this part doesn’t fully develop until we are in our early 20s.
Meanwhile, teen brains get more excited from rewards (奖励). The parts of the brain that make us feel good when we do something enjoyable — like eating tasty foods — are fully developed by the teen years.
In fact, these parts are even more sensitive when we are young. That’s because dopamine (多巴胺 ), a natural chemical that makes us feel happy when we experience something good, is especially active in teenage brains.
Therefore, the teen brain has two attacks against it when it comes to saying no to junk food. “It has an increased drive for rewards and reduced self-control,” said Reichelt.
Reichelt and her team did their own study using mice, whose brains develop much like our own. They discovered that “teenage” mice that had high-fat foods performed worse on memory tests than those eating normal foods. Researchers said the high-fat foods may make the mice’s prefrontal cortex work less effectively.
So, what’s the best way to say no to junk food? The answer is exercise. When we exercise, the brain becomes less sensitive to food, besides this, it also helps our brains grow and become better able to make wise decisions and control our behaviors.
【小题1】What does the first paragraph mainly talk about?| A．What problems are caused by junk food. |
| B．What junk food teenagers like most. |
| C．How junk food harms teenage brains. |
| D．How junk food shapes teenage brains. |
| A．Teenagers are less sensitive than any other age group to junk food. |
| B．Junk food may make people’s prefrontal cortex work less effectively. |
| C．Dopamine helps our brains become better able to make wise decisions. |
| D．The prefrontal cortex makes us happy when we do something enjoyable. |
| A．Teenage Brains | B．Healthy Food for Teenagers |
| C．Food for Thought | D．Exercise: the Best for Brains |
①Sugar-free cookies, reduced-sugar cereal, sugar-free candy, diet soda. Do these seem like healthier alternatives (替代物)? After sugar became something forbidden in the nutrition and fitness world, sugar-free products acted as alternatives for once beloved sweet drinks and snacks. Claiming to be ZERO sugar, they were believed as healthier choices, especially for those people who manage diabetics (糖尿病), or aim to slim down. But the truth is they aren’t equal to better.
②When a product is labeled sugar-free, it means artificial sweeteners are used instead of real sugar. Artificial sweeteners don’t come from natural sources but they are chemical substances that are added to food and drinks to make them sweeter. Actually, most artificial sweeteners are a lot sweeter than sugar, even 200—600 times sweeter, so only a tiny amount is needed.
③Let’s find out how artificial sweeteners work. They work similarly to regular sugar by exciting your taste buds. The taste buds send signals to the brain that they have tasted something sweet and you feel a similar sense as you would with sugar.
④In recent studies, scientists have revealed artificial sweeteners are more harmful to our body than real sugar. Many businesses market sugar-free alternatives as “low-calorie” or “no-calorie”. It misleads people to believe sugar-free products can make them slim and healthy. But it’s reported that you get no nutritional value from consuming them.
⑤What’s worse, when you eat this kind of sweet food, your body continues to desire it even though your body can’t metabolize (新陈代谢) these sugar-free alternatives. Your brain does not know the difference, either. In turn, sugar-free alternatives connect to weight gain and Type 2 diabetes.
⑥Similarly, artificial sweeteners also damage your gut’s ability to break down sugar which affects everything you eat. In other words, your body doesn’t know how to deal with artificial sweeteners because they have nothing real to process.
⑦Here’s a golden rule: stay away from artificial sweeteners and look for non-sugar, natural sweeteners like Stevia or date sugar. In the war against artificial sweeteners and real sugar, both lose. Satisfy your sweet tooth with natural sugars that come from fruits and stay away from products claiming to be sugar-free or diet!
【小题1】What’s special about sugar-free products?| A．They don’t taste delicious. | B．They are good for health. |
| C．They can make people excited. | D．They contain artificial sweeteners. |
| A．using | B．storing | C．breaking | D．controlling |
| A．People should fight against sugary products and stay away from them all the time. |
| B．People who like sweet food can choose fruit sugars to improve their ability to metabolize. |
| C．It’s wise for people to refuse artificial sweeteners because they result in some health risks. |
| D．There is still a need for more scientific studies on sugary products whether they are safe or not. |
A． | B． |
C． | D． |
When packing a lunch, you need to remember the rules about food safety.
根据材料内容从下面五个选项中选出能填入文中空缺处的最佳选项，使短文意思通顺内容完整，并将其标号填写在下面题号后的横线上。
| A．Clean your lunch box immediately. |
| B．Start with a clean kitchen. |
| C．Make sure to put your lunch in a cooler place. |
| D．It is important to keep pets off the table. |
| E．Use fresh foods to make the lunch. |
How to be a HEALTHY COOK | |
| As more research warns the danger of overcooking, an expert tells us how we can make mealtimes healthier with the right kitchen Know-How. | |
| The Food Standards Agency (FSA) has recently started an activity to help people understand the danger of being exposed to acrylamide (丙烯酰胺), a possible cancer-causing chemical, while cooking at home. According to some scientific research, overcooking can cause cancer, so we should try to keep a golden yellow colour or lighter when frying, baking or roasting foods such as potatoes, root vegetables, and bread. “The risks of overcooking food are two-fold,” explains the expert. “Many nutrients (营养物) like some vitamins are damaged by heat and therefore cooking can destroy some of the goodness in certain foods such as fruit and vegetables. What’s worse, certain foods are believed to cause cancer when cooked.” | So, how can we cook up delicious meals without hurting health? |
| SHOP SMARTER Although it is nearly impossible to completely avoid acrylamide, it’s worth knowing which products contain it. Acrylamide is a chemical that is produced when starchy (淀粉类) foods are heated to very high temperatures for longer periods and is found in a wide range of foods, including chips, cakes and bread. The expert explains, “There are no clear guidelines on the ‘safe’ level of acrylamide that a person can eat, so try to reduce eating it whenever possible instead of trying to completely get rid of it, which could be so hard.” The way we store our food can also increase acrylamide levels. The FSA advises keeping raw potatoes for frying in a dark, cool place at a temperature above 6°C instead of putting them in a fridge. | |
SPEED IT UP, SAFELY Microwaving is a convenient choice. It uses a small amount of water and cooks food from the inside out, allowing for a shorter cooking time. The expert suggests that if you’re short on time, microwaving can be a convenient way to cook food without damaging its nutrients. | |
| A．It has no known bad effects on people’s health. |
| B．It may increase the risk of getting cancer in humans. |
| C．It may cause serious health problems like heart attack. |
| D．The effects of acrylamide on human health are unclear. |
| A．Some nutrients and the goodness in certain foods are lost. |
| B．Overcooked foods usually taste terrible and smell bad. |
| C．Overcooked foods are believed to make people fatter. |
| D．It can destroy vitamins found in potatoes and meat. |
| A．They become much sweeter. | B．They become too hard to eat. |
| C．They have an orange colour. | D．They produce acrylamide. |
| A．Heat food to high temperature in a short time. | B．Reduce taking foods heated for long periods. |
| C．Avoid microwaving though it is convenient. | D．Store food for frying in a fridge below 6°C. |
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