2 . Most of us want to get in shape and be healthy. For many of us nutrition (营养) and watching what we eat is an important way to stay healthy. But when it comes to food, what is calorie counting, and what are the positives and negatives of it?

A law in the UK came into force in April 2022 that requires restaurants, takeaways, and cafes to display the calorie information of non-pre-packed food and soft drinks on their menus. It’s a strategy aimed to deal with obesity and give people a more informed choice of what goes down into their stomachs. Being able to count calories and know how much we can eat is a great way to try and stay on track with our diet.

However, there are some disbelievers when it comes to calorie counting 200 calories of fresh fruit and 200 calories of junk food, for example cookies, have the same caloric value. However, there is a question of the health benefits of what you’re eating, regardless of calories. While fresh fruit like apples contains things like vitamin C, junk food could contain an unhealthy level of sugar and fats. Likewise (同样地), fruit may fill you up and leave you not wanting more food for longer than a biscuit with equal calories —meaning, overall, you eat less.

Simply counting calories, while useful for weight loss, doesn’t take into account your intake of good fats, carbohydrates, and proteins—things that your body needs. So, if you’re trying to stick to a low-carbon diet, just looking at numbers of calories on a menu won’t be that useful. So, always be mindful that what you’re eating is part of a healthy balanced diet.

4 . That artificial food dyes (染料) are unhealthy is not news. Some are known to cause hyperactivity (多动症) in some children, affecting their ability to learn. But regulatory agencies (监管机构) around the world don’t necessarily agree on which food dyes are a problem, or why. That may soon change. A 2021 peer-reviewed report by California’s Office of Environmental Health Hazard Assessment concluded that artificial food dyes “cause or worsen neurobehavioral (神经行为的) problems in some children” and that the current levels that are regarded safe for consumption by the federal government are too high.

California is now considering requiring warning labels on food products and dietary supplements containing the seven most commonly used artificial dyes. The warning label requirement would put California on par with the European Union, which since 2010 has required food products containing certain artificial food dyes to carry warning labels about their negative effect on activity and attention in children.

Artificial dyes are used in foods for one reason: to make products look prettier. Bright colors make candies appealing, especially to kids. But dyes are also in chocolate cake mixes, salad dressings and other products that don’t seem to cry out for a color boost.

In Europe, it was the 2010 label lawmaking that triggered (引发) companies’ decisions to reformulate. “If you’re a company, you do not want to put a warning label on your product.” says Lefferts, an environmental health consultant. Warning labels are why European Starburst Fruit Chews are now colored with natural products, not the artificial dyes that brighten their North American counterparts (同类商品).

Given that artificial food dyes are used far more than needed, we need to be more cautious. After all, we don’t dye fresh fruits and vegetables, but we do dye candy and sprinkles, points out Joe Schwarcz, a chemistry professor at McGill University in Montreal. “The foods in which you find food dyes are foods that are poor in nutrition,” he says. “If you limit foods that contain food dyes, you automatically make your diet better.”

8 . Mice were given a memory test in a lab at the University of New South Wales, in Australia. Scientist Margaret Morris set them in their usual box, but she rearranged the objects in the box. Some mice smelled them curiously, but others just moved on. They didn’t remember the objects were once in a different place.

The mice with sharper memory were fed with a regular diet of low-fat, healthy food. However, the mice that ate lots of junk food for two weeks — such as cake, meat pies, chips, and cookies — were forgetful.

Food can have the same effect on people, too. “If you’re eating junk food regularly, and not eating enough fruit and vegetables,” Morris said, “the changes inside your body may be affecting brain function.” Changes inside the body can affect a person’s overall health, too.

Scientists have long known that the brain communicates with the stomach to control digestion. Recently, they have found that the stomach talks back. It may even tell the brain what to do.

Foods with too much salt and sugar affect the microbiome (肠道菌群) in your body by killing the right bacteria (细菌) in it. These bacteria protect you from illness and keep your mind sharp. Lacking them can lead to being overweight and depression.

Robert Knight is a scientist at the University of California, San Diego. He suggests eating yogurt, because it is packed with healthy bacteria. Does that mean no French fries? “Having them sometimes is okay,” Knight says. “It’s the long-term habits that really matter. Being good to your microbiome over the next six months is a lot more important than what you ate yesterday, or what you eat tomorrow.”