It's no surprise that holiday feasts often bring expanding waistlines, but a new study finds that weekend eating can also be a cause for concern.

    Some people chow down more calories on Saturday and Sunday than on a typical weekday, researchers find. The study also showed that people tend to keep track of how much they are consuming on a daily basis, at least in a rough sense. Specifically, if they skimped on breakfast, they would make up for it by gorging at lunch, more or less.

    The results suggest that those wanting to lose a few （or keep from putting on a few over the holidays） may want to think about their eating habits on a weekly basis rather than day-by-day.

    "Being forewarned is forearmed in this regard," said J. Jeffrey Inman, a professor of marketing at the University of Pittsburgh. "If you monitor your intake during the week you can kind of make sure you don't go too crazy on the weekends."

    Over the last 30 years, the obesity rate in the United States has increased dramatically, going from about 15 percent in the years 1976-1980 to about 33 percent of adults aged 20 to 74 in 2003-2004.

    Inman and his colleague Adwait Khare, of Quinnipiac University in Connecticut, wanted to see if patterns in people's eating habits could help to explain the fat statistics.

    They used data collected in 1998 and 1999 on the eating habits of about 600 individuals who had participated in a national survey conducted annually by NPD group, a market research firm that collects this information for American food companies. The results were published in the Fall 2009 issue of the Journal of Public Policy & Marketing.

    For each survey, participants kept track of the foods eaten by everyone in their household over a two-week period. Self-reports are prone to errors, though Inman thinks the results are actually conservative since people tend to forget to report or underestimate how much they consumed.

    Among the patterns revealed:

    If participants consumed more calories at one meal they tended to eat less at the next. But if they ate a light meal for breakfast, they'd down more calories for lunch or dinner.

    About 84 percent of the participants tended to group their meals on a daily basis, with meals eaten during one day having a stronger effect on each other than meals eaten over adjoining days.

    On average, people ate 37 calories more on the weekends than weekdays, mostly at breakfast. The researches speculate this breakfast bump may be due to people having more time to eat on weekend mornings.

    Participants who ate more on weekends than weekdays at all three meals - breakfast, lunch and dinner - devoured as much as 400 calories more on weekends, a 20-percent increase.

    Participants who skimped on the weekends for all three meals compared with weekdays, ate as little as 400 calories less on weekends than on weekdays.

    The takeaway message for consumers: "I need to monitor myself and make sure I don't fall into the 400-over group on the weekends," Inman said.

    Some of the biggest jumps in calories came on holidays, particularly those centered on feasts, such as Thanksgiving and Christmas.

    For instance, participants ate an average of 174 calories more on holidays than on non-holidays, and this increase usually came at lunchtime. However, some people ate more than 900 calories extra on holidays compared to non-holidays, a 46-percent increase for that group.

    However, while holiday grubbing may be bad for your diet, over-eating on the weekend may be just as detrimental because "there's a lot more weekends than there are holidays," Inman said.

    The findings indicate that people may want to think beyond their daily calorie intake. "Our results suggest you need to think between days, because if you have a big dinner last night, then those calories don't disappear, they're with you today,"

    Most adults eat between 1,800 and 2,500 calories per day. Having a weekly budget of calories might be useful to consumers, Inman said. "If you think of it in a little broader terms, say 14,000 [to] 15,000 calories for the week, I think you'd be much better able to monitor the highs and lows for the week."

    众人皆知节日大吃盛宴经常会导致腰围变粗，而一项新研究发现，周末进餐也会成为烦恼之源。

    研究人员发现，有些人在周六和周日吸收的卡路里多于平日。该研究也表明人们往往留意他们平均每天吃多少，至少粗略的这样估算。具体说，如果他们没吃早饭，他们午饭就要大吃一顿大致补齐。

    研究结果表明，那些想减轻几磅或不想在节假日增加体重的人会考虑一周的饮食习惯，而不是天天如此。

    "在这方面提前警告有备无患"匹兹堡大学销售学教授Jeffrey Inman 说，"如果全周都监控你的进食量，你就有几分把握在周末不会过于疯狂。"

    过去三十年间，美国的肥胖率显着增加，1976-1980期间占大约15%,2003-2004年龄在20到74之间的成年人肥胖率已达到约33%.

    Inman和他的同事，康涅狄格州Quinnipiac大学的Adwait Khare想研究人们的饮食习惯模式是否对解释这些肥胖数据有所帮助。

    他们使用的数据是1998和1999年收集的，当时共有大约600人参加了由NPD集团一年一次进行的关于个人饮食习惯的全国调查。NPD是为美国食品公司采集信息的市场研究所。Inman和Adwait Khare的研究结果在《公共政策与营销杂志》2009秋季版刊登。

    针对每一项调查，参加者要追踪家中每个人在两周的时间里的饮食。尽管Inman认为结果确实很保守，但因为人们总是忘记汇报或低估饭量，自我报告容易有误差。