英语六级 2023年3月·第1套 Part III Section C (2) 阅读理解（四选一）试卷排版

The suggestion that people should aim for dietary diversity by trying to eat a variety of foods has been a basic public health recommendation for decades in the United States and elsewhere. Now, however, experts are warning that aiming for a diverse diet may actually lead to just eating more calories, and, thus, to obesity. One issue is that people may not interpret "variety" the way nutritionists intend. This problem is highlighted by new research conducted by the American Heart Association. Researchers reviewed all the evidence published related to dietary diversity and saw a correlation between dietary diversity and a greater intake of both healthy and unhealthy foods. This had implications for obesity, as researchers found a greater prevalence of obesity amongst people with a greater dietary diversity.

One author of the new study explained that their findings contradict standard dietary advice, as most dietary guidelines around the world include a statement of eating a variety of foods. But this advice does not seem to be supported by science, possibly because there is little agreement about the meaning of "dietary diversity," which is not clearly and consistently defined. Some experts measure dietary diversity by counting the number of food groups eaten, while others look at the distribution of calories across individual foods, and still others measure how different the foods eaten are from each other.

Although the findings of this new study contradict standard dietary advice, they do not come as a surprise to all of the researchers involved. Dr. Rao, one of the study authors, noted that, after 20 years of experience in the field of obesity, he has observed that people who have a regimented lifestyle and diet tend to be thinner and healthier than people with a wide variety of consumption. This anecdotal evidence matches the conclusions of the study, which found no evidence that dietary diversity promotes healthy body weight or optimal eating patterns, and limited evidence that eating a variety of foods is actually associated with consuming more calories, poor eating patterns and weight gain. Further, there is some evidence that a greater variety of food options in a single meal may delay people's feeling of fullness and actually increase how much they eat.

Based on their findings, the researchers endorse a diet consisting of a limited number of healthy foods such as vegetables, fruits, grains, and poultry. They also recommend that people simultaneously endeavor to restrict consumption of sweets, sugar and red meat. The researchers stress, however, that their dietary recommendations do not imply dietary diversity is never positive, and that, in the past, diversity in diets of whole, unprocessed food may have actually been very beneficial.