来源：《新科学家》
原文刊登日期：2022年1月5日
It sounds simple: eat less and move more. This dietary advice for tackling obesity has been around for decades. Yet, despite all the calorie counting, dieting and exercising, worldwide obesity rates just keep ticking up. People in the US, for example, were heavier in 2021 than they were in 2020, placing many more people at risk from diabetes and other serious chronic diseases. So why hasn’t this approach to weight control worked?
这听起来很简单：少吃多动。这种解决肥胖问题的饮食建议已经存在了几十年。然而，尽管人们在计算卡路里、节食和锻炼，世界范围内的肥胖率还是在不断上升。例如，美国人在2021年比2020年更重，这使更多的人面临糖尿病和其他严重慢性疾病的风险。那么，为什么这种控制体重的方法不起作用呢？
One possibility is that we haven’t tried hard enough. Perhaps we have lacked the discipline and willpower to maintain healthy dietary and exercise habits.
一种可能是我们还不够努力。也许我们缺乏自律和毅力来保持健康的饮食和锻炼习惯。
Or perhaps the problem is the focus on “calorie balance” itself. A recent paper questions the basic assumption of whether taking in more calories than you burn really is the primary cause of obesity. The paper argues that the evidence actually points the other way: we are driven to overeat because we are getting fatter.
或许问题出在“热量平衡”本身。最近的一篇论文质疑了一个基本假设，即摄入的热量比燃烧的热量多，是肥胖的主要原因。这篇论文认为，证据实际上指向了另一个方向：我们之所以暴饮暴食，是因为我们越来越胖。
This may seem incredible, but consider the adolescent growth spurt. As their growth rate speeds up, teenagers may eat hundreds of calories more each day than they used to. Does this “overeating” cause the rapid growth? Or does the rapid growth, which requires more calories to build new body tissues, make teens hungrier so they eat more? Clearly the latter, as adults won’t grow taller, no matter how much they eat.
这似乎难以置信，但想想青春期的快速成长吧。随着生长速度的加快，青少年每天可能会比以前多摄入数百卡路里。是“暴饮暴食”导致了快速增长吗？还是因为快速生长需要更多的卡路里来构建新的身体组织，所以青少年会更饿，所以吃得更多？显然是后者，因为成年人不管吃多少，都不会长高。
The key to how this works in obesity is hormones, especially the fat-storage hormone insulin. Processed, rapidly digestible carbohydrates – foods like potato chips and sugary beverages – raise our insulin level too high. This causes our fat cells to take in and store too many calories, leaving fewer available for the rest of the body. A few hours after eating a high-carb meal, the number of calories in the bloodstream plummets, so we get hungrier sooner after eating.
肥胖的关键在于激素，尤其是脂肪储存激素胰岛素。加工过的、可快速消化的碳水化合物——像薯片和含糖饮料——会使我们的胰岛素水平过高。这会导致我们的脂肪细胞吸收和储存过多的卡路里，留给身体其他部位的热量就会减少。吃了一顿高碳水化合物的饭几个小时后，血液中的卡路里数量就会直线下降，所以我们在吃完饭后很快就会感到饥饿。
The two opposing views of cause and effect in obesity have radically different implications for how to prevent and treat weight problems. Whereas the usual approach focuses on how much to eat, with prescriptions for daily calorie intake, the paper argues the emphasis should be placed on what to eat.
这两种关于肥胖因果关系的对立观点对于如何预防和治疗体重问题有着根本不同的含义。通常的方法关注的是吃多少，以及每天的卡路里摄入量，而这篇论文认为，重点应该放在吃什么上。
Replacing processed carbs with high-fat foods – such as nuts and chocolate – lowers insulin levels, making more calories from the meal available for the rest of the body. Counter-intuitively, higher-fat foods may help shed body fat.
用高脂肪食物(如坚果和巧克力)代替加工过的碳水化合物，可以降低胰岛素水平，为身体的其他部分提供更多的卡路里。与直觉相反，高脂肪的食物可能有助于减少体内脂肪。
This way of thinking might help explain why calorie restriction usually fails long before a person with obesity approaches an ideal body weight. A low-calorie, low-fat diet further restricts an already limited supply of energy to the body, exacerbating hunger without addressing the underlying tendency to store too many calories in body fat. Consequently, weight loss becomes a battle between mind and metabolism that most people will probably lose.
这种思维方式可能有助于解释为什么在一个肥胖的人接近理想体重之前，卡路里限制通常就失效了。低卡路里、低脂肪的饮食进一步限制了身体本已有限的能量供应，加剧了饥饿感，却没有解决身体脂肪中储存过多卡路里的潜在倾向。因此，减肥成为一场精神和新陈代谢之间的战争，大多数人可能会输。
Although much more research will be needed to test this provocative idea, it is time to question the basic assumptions about cause and effect, calories and weight gain that have dominated our thinking for decades.
虽然还需要更多的研究来验证这个颠覆性的想法，但现在是时候质疑几十年来主导我们思维的关于因果、卡路里和体重增加的基本假设了。