If there's one place where it's a good idea to come clean, it's the doctor's office. Patients with an ache, a symptom or a bad habit like smoking do no one any good if they keep it to themselves. Yet there's one time doctors are often less than forthcoming: when they have to tell patients they need to lose weight.

Researchers at the Mayo Clinic in Rochester, Minn., recently released the results of a survey of more than 2,500 obese patients who went to their doctor for a regular checkup over the course of a year. The investigators found that the charts of only 1 in 5 of those people listed them as obese. What isn't on the charts is probably not communicated between doctor and patient either, and that means trouble. Those in the study who got the diagnosis were more than twice as likely to have developed a weight-management plan with their doctor than were the other obese patients.

"If you don't have a plan, you're not going to lose weight," says the study's author, preventive-medicine specialist Dr. Warren Thompson, whose research was published in August's Mayo Clinic Proceedings.

Obesity, of course, means a higher risk of heart disease, diabetes, hospitalization and early death, so how come doctors are so lax about putting the scarlet O on the chart? Sometimes, Thompson says, doctors perceive that a patient isn't motivated to change, so they just don't bother. Other times, the patient's likely embarrassment silences the physician, or time constraints get in the way as more immediately pressing health concerns get dealt with.

Discussing weight becomes even more complicated with children. According to a 2005 study in the journal Pediatrics, doctors diagnosed obesity less than 1% of the time among 2-to-18-year-olds—a figure far below the one-third of young Americans struggling with weight.

Dr. Mark Jacobson, an adolescent-medicine specialist with the American Academy of Pediatrics, explains that parents may feel guilty about having an overweight kid because they know it's partly hereditary and because they feel it's their responsibility to control their youngster's exercise levels and diet. Parents also worry about a child's developing eating disorders if weight becomes an issue, so they say nothing at all.

"I've had a patient whose mother whispered the letters w-e-i-g-h-t to me, with her hand over her mouth so the child couldn't see. I could tell it was something they had thought about and didn't want to bring up with the child," says Jacobson. Still, he insists that doctors must discuss the topic. One way to do so gently, he says, is to avoid the word obese and instead say the child has a weight problem. Doctors may also tell kids that their weight is a couple of years ahead of their age. Then, Jacobson says, he focuses the discussion more on the behaviors that could help improve the situation—like watching less TV and playing outside more—instead of concentrating principally on shape.

"You don't want to make people feel embarrassed and not want to come back to you. You want them to get treated," he says. Jacobson stresses that every pediatrician should determine a child's body-mass index (BMI)—a figure arrived at by factoring weight and height to produce a two-digit number that roughly diagnoses obesity. BMI is an imperfect metric, in part because it does a poor job of taking body type and muscle mass into consideration, meaning that a stocky person with low body fat can be labeled obese. But as a starting point, BMI helps.

None of this absolves patients or parents from stepping forward and bringing up weight on their own. But whoever raises the topic, it's important for patients and doctors alike to remember that modest amounts of weight loss can disproportionately benefit overall health, even if the loss doesn't feel or look like much. That fact may be the best reason for everyone to show a little courage and say what needs to be said — even if it hurts a bit.

有個地方你去了最好是老實交代，這地方就是醫生診療室。頭疼腦熱，大癥小狀，抽煙等壞毛病醫生都問得清清楚楚，悶著不說出來可一點兒好處都沒有。然而，醫生也有猶豫的時候：當他們不得不告訴病人，該減肥了。

明尼蘇達州梅奧診所的研究人員最近公布的一個項調查結果顯示：接受醫生定期檢查一年的2500多名肥胖患者中，僅有1/5的人登記為肥胖癥。沒有在列的人員很可能也沒有進行醫患雙方的交流。這就意味著不正常。參與研究的病例中，那些得出診斷結論的病人與醫生合作控制體重的概率是那些沒有登記的肥胖病患的兩倍多。

“如果沒有減肥計劃，體重一般不會降低，”該研究報告的作者，預防醫學專家沃倫湯普森博士說，他的研究結果發表在梅奧診所的公報中。

當然，肥胖意味著更接近心臟病、糖尿病、住院和提早死亡。那為什么醫生不及時在診斷書上把肥胖這項勾出來呢？有時候，湯普森說，醫生覺得某個患者主動減肥的熱情不高，他們也就不庸人自擾了。其他時候，醫生顧忌到患者可能會覺得尷尬，還有時候是其他更迫切的健康問題阻撓了肥胖問題的提出和解決。

青少年肥胖問題更為復雜。根據兒科雜志2005年的調查研究，在2到18歲的青少年中，只有不到1%的人被醫生診斷為肥胖癥，而約1/3的美國青年遭受肥胖困擾。

美國兒科學會的青少年醫學專家馬克·雅各布森博士解釋說，如果醫生說出實情，父母們可能會為擁有一個過重的孩子感到內疚，因為父母會覺得肥胖癥部分是遺傳問題，而且他們覺得自己要對控制子女的活動量和飲食負責。如果肥胖被提上日程，父母還會擔心孩子們在成長時期飲食是不是不規律，所以醫生們都絕口不提。

“有個患者的母親低聲做出‘肥胖’兩字的口型，還用手擋著她的嘴，怕她孩子看到。我可以看出父母們也在思考這個問題，但是他們不想帶給孩子這種困擾，” 雅各布森說。但是他仍然堅持討論這個話題。有一個婉轉一點的辦法，他說，就是避免“肥胖”這個字眼，可以說孩子有體重問題。醫生還可以對孩子們說他們的體重比他們的年齡長得快了兩年。然后，雅各布森將討論的重點更多地放到了什么樣的習慣能改變這種局面—像少看電視，多進行戶外活動—而不是就體型問題抓著不放。“你也不想讓患者感到尷尬從此再也不來你這里了。你希望的是他們得到治療，”他說。雅各布森強調每一個兒科醫生都應該確定孩子的身體重量指數（BMI）--一組通過身高除以體重得出的數據，能大致診斷是否患有肥胖癥。BMI是個不完美的公式，部分是因為它沒有將體重與肌肉很好地結合考慮，也就是說，一個矮小結實沒有肥肉的人可能測出來是肥胖。但是作為初診，BMI是有幫助的。

這些對于患者和其父母勇敢說出并停止發胖本身并沒有幫助。但是無論誰提出問題來，病患和醫生都要記得，即使有時候看不出也感覺不出減了多少，適當減肥能或多或少地對全面健康有幫助。這個事實可能是鼓勵每個人表現出一點勇氣來說出肥胖困擾---即使有點尷尬。