在多样化的饮食和其他生活方式因素与长期体重增加之间的相关性是如何变化的这样一系列三个独立的研究中，哈佛公共卫生学院(HSPH)的研究人员发现，适度的改变特定的食物、饮料、体育活动、看电视，和持续睡眠，与长期体重增加密切相关。尤其是饮食变化，与体重增加有最强的联系。
该研究发表于2011年6月23日发行的《新英格兰医学杂志》上。
以前的研究通常专注于肥胖形成之后的减肥方法。与长期体重增加有关的因素一直不太明朗。
成年人平均每年大约增加一磅。
“成年人平均每年大约增加一磅。许多年来体重增加是如此的频繁，科学家们和个人自己已经很难理解具体的因素影响”，第一作者Dariush Mozaffarian说，HSPH流行病学系的副教授和布莱根妇女医院(BWH)、哈佛大学医学院心血管医学部的副教授。
研究人员评估了多重特定生活方式因素变化，和护士健康研究(NHS)、护士健康研究II(NHSII)、保健专业随访研究(HPF)三个独立的研究组12至20年随访之后每四年一次的体重增长。最后的分析包括NHS 的50422名女性、 NHS II 的47898名女性、HPFS的22557名男性，,他们中的所有人在最初研究时都是不肥胖的。研究参与者在每四年中体重平均增加了3.35磅 ，在过去20多年中体重增加了16.8磅。,
当对生活方式的改变与体重增加的相关性进行评估时，结果是在所有三个组的研究惊人地相似。
例如，在过去20年最能使体重增加的食品包括薯片(每四年使体重增加超过 1.69磅)，其他土豆(1.28磅)，含糖饮料(1.00磅)，未加工肉(0.95磅)，和加工肉类(0.93磅)。注意，一些使体重减轻的食物实际上是增加了消耗，包括蔬菜(0.22磅)、全谷类(0.37磅)、水果(0.49磅)，螺母(0.57磅)和酸奶(0.82磅)。当对所有饮食改变全面评估时，少于20%改变了饮食的参与者比多于20%的的人每四年体重平均增加了几乎4磅，——与全部人口整体平均体重增加的情况是大致等同的。
研究人员说，对节食而言，只聚焦在总热量上可能不是最有用的方法，可能消耗了一个人最低限度的热量。其他的标准，如总脂肪的内容、能量密度或糖，可能也会造成误导。相反，他们发现食用健康食品和饮料，关注整体饮食质量，才是最重要的。
预防长期的体重增加最有效的饮食似乎是:
•通过吃更少的液体糖(例如苏打) 和其他糖类物质来改善碳水化合物质量，以及更少的淀粉(如土豆)和精制谷类(如白面包、白米、早餐低纤维麦片、其他精细加工后的碳水化合物)。
•多吃最低限度加工加工的食品(如水果、蔬菜、全麦、坚果、酸奶酪)和更少的精加工食品(如白面包、加工过的肉、糖饮料)。
这样一个更健康的饮食模式可能在许多方面影响长期体重增加,比如在生物的影响方面，通过饥饿、胰岛素水平，或过饱，或改进食物和饮料的的消费模式和平均份量的饮食习惯。
“这些发现强调在防止体重增加和肥胖方面作出明智食物选择的重要性，”弗兰克说，HSPH营养和流行病学系的教授和报纸的作者。“没有”好“或”坏“食物这样的观点是一个需要反驳的神话。”
结果显示了体育活动和看电视最体重影响的不同。而且,那些一晚睡了6-8小时的人比那些睡眠时间少于6或超过8小时的人体重增加的更少。
总的来说,任何一个生活方式的改变带来的体重变化是相当小的。然而，如果这些因素加在一起，特别是饮食，“很小的饮食改变和其他生活方式的改变，加在一起就可以造成很大的差异——可以是坏的或者是好的”，Mozaffarian说。“这无意中很容易导致发胖，而且证明了预防有着非常大的机会。很少的正确的生活方式的改变将大有帮助。”
这项研究是由美国国家卫生研究院和塞尔学者计划支持的。
生物探索推荐英文原文：
Changes in Diet and Lifestyle and Long-Term Weight Gain in Women and Men
BACKGROUND
Specific dietary and other lifestyle behaviors may affect the success of the straightforward-sounding strategy “eat less and exercise more” for preventing long-term weight gain.
METHODS
We performed prospective investigations involving three separate cohorts that included 120,877 U.S. women and men who were free of chronic diseases and not obese at baseline, with follow-up periods from 1986 to 2006, 1991 to 2003, and 1986 to 2006. The relationships between changes in lifestyle factors and weight change were evaluated at 4-year intervals, with multivariable adjustments made for age, baseline body-mass index for each period, and all lifestyle factors simultaneously. Cohort-specific and sex-specific results were similar and were pooled with the use of an inverse-variance–weighted meta-analysis.
RESULTS
Within each 4-year period, participants gained an average of 3.35 lb (5th to 95th percentile, −4.1 to 12.4). On the basis of increased daily servings of individual dietary components, 4-year weight change was most strongly associated with the intake of potato chips (1.69 lb), potatoes (1.28 lb), sugar-sweetened beverages (1.00 lb), unprocessed red meats (0.95 lb), and processed meats (0.93 lb) and was inversely associated with the intake of vegetables (−0.22 lb), whole grains (−0.37 lb), fruits (−0.49 lb), nuts (−0.57 lb), and yogurt (−0.82 lb) (P≤0.005 for each comparison). Aggregate dietary changes were associated with substantial differences in weight change (3.93 lb across quintiles of dietary change). Other lifestyle factors were also independently associated with weight change (P<0.001), including physical activity (−1.76 lb across quintiles); alcohol use (0.41 lb per drink per day), smoking (new quitters, 5.17 lb; former smokers, 0.14 lb), sleep (more weight gain with <6 or >8 hours of sleep), and television watching (0.31 lb per hour per day).
CONCLUSIONS
Specific dietary and lifestyle factors are independently associated with long-term weight gain, with a substantial aggregate effect and implications for strategies to prevent obesity. (Funded by the National Institutes of Health and others.)
Supported by grants (DK46200, DK58845, HL085710, HL60712, HL35464, CA87969, CA50385, CA55075, and CA95589) from the National Institutes of Health and by the Searle Scholars Program.
Dr. Mozaffarian reports receiving consulting fees from Nutrition Impact and Foodminds, lecture fees from Aramark, Unilever, and SPRIM, royalties from UpToDate, and grant support on behalf of Harvard Medical School from GlaxoSmithKline, Sigma-Tau, and Pronova and being listed as a coinventor on a provisional patent application filed by and assigned to Harvard University for the use of trans-palmitoleic acid to prevent and treat insulin resistance, type 2 diabetes, and related conditions. Dr. Hu reports receiving lecture fees from Amgen, Nutrition Impact, Unilever, and the Institute of Food Technologies and grant support on behalf of the Harvard School of Public Health from Merck and the California Walnut Commission.
