When it comes to losing weight, the most important rule of thumb is to consume fewer calories than you're taking in each day. But cutting calories doesn't have to mean eating less food. In fact, simply focusing on healthier food choices may be a more sustainable weight-loss strategy than trying to reduce portion sizes, a new Penn State University study suggests.

说到减肥这个话题，最重要的经验法则就是：每天摄入的卡路里量少于往常的摄入量。但减少卡路里的摄入量并不一定意味着少吃食物。宾夕法尼亚州立大学的一项新研究表明：事实上，相比减少食物分量，关注更健康的食物可能是更可持续的减肥策略。

The findings come from a small new clinical trial, published in the journal Appetite, which compared food consumption among 39 women who'd taken part in a previous, year-long weight-loss study and 63 women who were not part of the earlier study. All of the women came to the study lab once a week for four weeks to eat a meal, with varying portions of seven different foods served each week.

研究发表在Appetite期刊上，研究结果源于一项小型的新的临床试验，将先前参与为时一年的减肥研究的39位女性的食物摄入与没有参与这项研究的63位女性的食物摄入进行对比。所有女性每周都来实验室吃一顿饭，连续四周，每周有7种不同的食物、不同的分量。

The women in the first group, as part of the previous study, had been counseled on various strategies for weight loss, including measuring out portion sizes, calculating calorie density of different foods, and making overall healthier choices. Because the training focused heavily on portion control, the researchers expected the women who'd participated in those training sessions to eat less food overall.

第一组的女性（参与了先前的研究）已经知道了各种各样的减肥方法，包括量好食物分量、计算不同食物的卡路里密度、做出总体更健康的选择。因为先前的训练主要集中于分量控制，所以研究员预期参与这些训练的女性会吃更少的食物（整体而言）。

That didn't happen, though. Women in both groups fell victim to the "portion size effect," what researchers call the tendency to eat more when larger portions of food are presented. (For example, when meal size increased by 75%, the average amount consumed went up 27%.) Overall, there was no significant difference in total amount of food consumed, by weight, between those who'd received training and those who had not.

但情况并非如此。两组女性都成为"分量效应"的受害者，研究人员认为这一效应就是，当面前有更大份额的食物时，人们往往会吃的更多。（比如，当食物分量增加75%的时候，平均摄入量增加了27%。）总的来说，对于接受训练的女性和没有接受训练的女性而言，摄入的食物总量并没有显著差别。

But there was one difference. "When we dug into their food choices, we found that the trained participants were selecting to eat more of the lower calorie-dense foods-like salad, for example-and less of higher calorie-dense foods, such as the garlic bread," says first author Faris Zuraikat, a graduate student in the department of nutritional sciences. In other words, even though they ate the same total volume of food, they consumed fewer calories.

但也存在一个差异。"当我们研究她们的食物选择时，我们发现：受训参与者更多的选择吃那些卡路里密度更低的食物--比如沙拉--不大吃那些卡路里密度更高的食物，比如蒜蓉面包，"营养科学系研究生、第一作者Faris Zuraikat说道。换言之，虽然她们摄入了相等的食物量，但她们摄入的卡路里量却更少。

When it comes to losing weight, the most important rule of thumb is to consume fewer calories than you're taking in each day. But cutting calories doesn't have to mean eating less food. In fact, simply focusing on healthier food choices may be a more sustainable weight-loss strategy than trying to reduce portion sizes, a new Penn State University study suggests.

说到减肥这个话题，最重要的经验法则就是：每天摄入的卡路里量少于往常的摄入量。但减少卡路里的摄入量并不一定意味着少吃食物。宾夕法尼亚州立大学的一项新研究表明：事实上，相比减少食物分量，关注更健康的食物可能是更可持续的减肥策略。

The findings come from a small new clinical trial, published in the journal Appetite, which compared food consumption among 39 women who'd taken part in a previous, year-long weight-loss study and 63 women who were not part of the earlier study. All of the women came to the study lab once a week for four weeks to eat a meal, with varying portions of seven different foods served each week.

研究发表在Appetite期刊上，研究结果源于一项小型的新的临床试验，将先前参与为时一年的减肥研究的39位女性的食物摄入与没有参与这项研究的63位女性的食物摄入进行对比。所有女性每周都来实验室吃一顿饭，连续四周，每周有7种不同的食物、不同的分量。

The women in the first group, as part of the previous study, had been counseled on various strategies for weight loss, including measuring out portion sizes, calculating calorie density of different foods, and making overall healthier choices. Because the training focused heavily on portion control, the researchers expected the women who'd participated in those training sessions to eat less food overall.

第一组的女性（参与了先前的研究）已经知道了各种各样的减肥方法，包括量好食物分量、计算不同食物的卡路里密度、做出总体更健康的选择。因为先前的训练主要集中于分量控制，所以研究员预期参与这些训练的女性会吃更少的食物（整体而言）。

That didn't happen, though. Women in both groups fell victim to the "portion size effect," what researchers call the tendency to eat more when larger portions of food are presented. (For example, when meal size increased by 75%, the average amount consumed went up 27%.) Overall, there was no significant difference in total amount of food consumed, by weight, between those who'd received training and those who had not.

但情况并非如此。两组女性都成为"分量效应"的受害者，研究人员认为这一效应就是，当面前有更大份额的食物时，人们往往会吃的更多。（比如，当食物分量增加75%的时候，平均摄入量增加了27%。）总的来说，对于接受训练的女性和没有接受训练的女性而言，摄入的食物总量并没有显著差别。

But there was one difference. "When we dug into their food choices, we found that the trained participants were selecting to eat more of the lower calorie-dense foods-like salad, for example-and less of higher calorie-dense foods, such as the garlic bread," says first author Faris Zuraikat, a graduate student in the department of nutritional sciences. In other words, even though they ate the same total volume of food, they consumed fewer calories.

但也存在一个差异。"当我们研究她们的食物选择时，我们发现：受训参与者更多的选择吃那些卡路里密度更低的食物--比如沙拉--不大吃那些卡路里密度更高的食物，比如蒜蓉面包，"营养科学系研究生、第一作者Faris Zuraikat说道。换言之，虽然她们摄入了相等的食物量，但她们摄入的卡路里量却更少。