阶梯减肥法有效且省钱

《美国医学会杂志》(JAMA)6月27日发表的一项研究显示，阶梯减肥干预与标准饮食-运动疗法一样有效，而且费用仅为后者一半(JAMA 2012;307:2617-26)。

这项研究由匹兹堡大学的John M. Jakicic及其同事在2个临床中心开展，纳入363例年龄18~55岁、体重指数25~40 kg/m2且无心血管疾病及可能影响体重或体力活动的代谢疾病或内科疾病的超重成人。受试者被随机分入标准饮食-运动干预组(165例)和阶梯干预组(198例)。

研究者对两组患者给予相同的有关饮食和体力活动的建议，目的是降低热量摄入及脂肪消耗。此外，研究者还提供饮食计划样本，并要求至24周时每周的中高强度活动时间达到300分钟。标准干预组受试者在18个月干预期间参加小组会议，起初是每周1次会议，持续6周，之后减至每月2次会议，直至12个月，最后6个月进一步减至每月1次会议。这些会议的重点是教育受试者培养和维持健康的饮食和运动行为，以及学习有利于长期行为改变的策略。

阶梯干预组的内容与传统干预组相同，但根据每3个月达到的特定体重目标的情况，对联系频率、联系类型和其他减肥策略进行了调整。第1步，研究者为受试者每月提供1次小组会议和3封邮件。如果受试者未能达到减肥目标，第2步每月增加1次10分钟的电话联系。如果仍未达到减肥目标，第3步每月再增加1次10分钟的电话联系。第4步每月增加1次个人面对面会谈。第5步每天用替餐奶昔和替餐棒来代替1顿正餐和1份零食。第6步每月用另1次个人面对面会谈来代替1次电话联系。

共有260例受试者(72%)完成为期18个月的干预。结果显示，两组的体重减轻模式不同。与阶梯干预组相比，标准干预组总体上体重减轻更多且更快。6个月时，标准干预组和阶梯干预组的体重分别平均减轻9.6 kg和7.6 kg。在基线至6个月这段时间内，标准干预组和阶梯干预组的体重减幅分别为10.4%和8.2%。18个月时，标准干预组和阶梯干预组的体重分别平均减轻7.6 kg和6.2 kg，差异不显著。在基线至18个月这段时间内，标准干预组和阶梯干预组的体重减幅分别为8.1%和6.9%。18个月时，两组在绝对体重方面的差异效应大小为6.3%，在体重减轻方面的差异效应大小为18%。从另一方面来看，两组达到体重减轻≥5%、≥7%和≥10%目标的人数相似，因此阶梯干预是替代传统干预的可行方法。

两组受试者的静息心率、收缩压和舒张压均显著降低，并且组间差异不显著。同样，两组受试者的体质水平(定义为达到年龄预测最大心率的85%所需的时间)的改善程度相同。阶梯干预法和标准干预法的费用分别约为785美元/人和1357美元/人。阶梯干预法的费用显著低于标准干预法，主要是因为阶梯干预法对面对面会谈的依赖较少。阶梯干预法的增量成本效益比为127美元/kg体重减轻，而标准干预法为409美元/kg体重减轻。

与既往研究比较后发现，上述干预方法的效果与其他药物和行为减肥方法的效果一样好。目前尚不清楚研究中观察到的体重减轻是否真正有助于改善健康相关预后。

该研究获美国国立卫生研究院和美国国立心肺血液研究所支持。研究者与Alere Wellbeing等公司存在联系。

爱思唯尔  版权所有

By: MARY ANN MOON, Cardiology News Digital Network

A stepped-care intervention for weight loss was nearly as effective as a standard behavioral diet-and-exercise approach but only cost about half as much, in a study of 363 overweight adults reported in the June 27 JAMA.

The overall weight loss during the 18-month intervention was greater with the standard approach. But, at the conclusion of the study, when both groups of subjects had regained some of their lost weight, the 1.3-kg difference between the two was not significant.

Moreover, the cost of the stepped-care program was estimated to be $785/person, compared with a $1,357/person price tag for the standard approach, according to John M. Jakicic, Ph.D., of the University of Pittsburgh, and his associates.

The stepped-care approach involves low-intensity intervention at first, which is escalated only if subjects fail to achieve their weight-loss milestones according to a fixed schedule. Stepped care has proved effective in the treatment of other conditions such as eating disorders, substance abuse, and anxiety disorders, the investigators noted.

In this study, performed at two clinical sites, adults aged 18-55 years with a body mass index between 25 kg/m2 and 40 kg/m2 were randomly assigned to a traditional diet-and-exercise program (165 subjects) or to the stepped-care program (198 subjects). All participants were free of cardiovascular disease as well as metabolic or medical conditions that might affect weight or physical activity.

The two groups received identical recommendations for diet and physical activity, aimed at reducing energy intake as well as fat consumption. They were offered sample meal plans and prescribed exercise that increased to 300 minutes/wk of moderate to vigorous activity by week 24.

For the standard intervention, subjects attended group sessions throughout the 18-month intervention, starting with weekly sessions for 6 weeks, decreasing to bimonthly sessions through 12 months, and further decreasing to monthly sessions for the final 6 months. These sessions focused on adopting and maintaining healthy eating and exercise behaviors, as well as learning strategies to facilitate long-term behavioral change.

For the stepped-care intervention, the content was the same but the "contact frequency, contact type, and other weight-loss strategies were modified, depending on the achievement of specific weight goals at 3-month intervals." In step 1, the subjects were offered one monthly group session and three mailings. If they failed to reach a weight-loss goal, step 2 added a 10-minute phone contact each month. If that also failed, step 3 added a second 10-minute phone call per month.

Step 4 added one individual, in-person session per month. Step 5 added replacement shakes and bars to take the place of one meal and one snack per day. Step 6 replaced one of the telephone contacts with a second individual, in-person session per month.

A total of 260 participants (72%) completed the 18-month intervention.

The pattern of weight loss was different between the two groups. Subjects in the standard-care group lost more weight overall and lost weight more quickly than did those in the stepped-care group.

With the standard intervention, subjects averaged a loss of 9.6 kg at 6 months, compared with a 7.6-kg loss in the stepped-care group. The percentage loss of weight from baseline to 6 months was 10.4% with the standard approach, compared with 8.2% with the stepped-care approach.

At 18 months, weight loss averaged 7.6 kg with the standard intervention and 6.2 kg with stepped care, a nonsignificant difference. The percentage loss of weight from baseline to 18 months was 8.1% and 6.9%, respectively. "The effect size for the difference in absolute weight at 18 months between the groups was 6.3%, and the effect size for the weight loss at 18 months between the groups was 18%," the investigators said.

Viewed another way, similar numbers of subjects in the two groups achieved weight losses of 5% or more, 7% or more, and 10% or more, so the stepped-care approach "may be a viable alternative to traditional [care]," the researchers concluded (JAMA 2012;307:2617-26).

Subjects’ resting heart rate, systolic blood pressure, and diastolic blood pressure decreased significantly in both groups, and there was no significant difference between the two groups. Similarly, subjects’ fitness level, defined as the time to achieve 85% of age-predicted maximal heart rate, improved to the same degree in both groups.

The cost of the standard approach was significantly higher mainly because of the reduced reliance on in-person meetings with stepped care. The incremental cost-effectiveness ratio for stepped care was $127/kg of weight lost, compared with $409/kg for standard care.

"Comparisons with the literature suggest these results are likely to compare favorably with other pharmacologic and behavioral weight loss interventions," Dr. Jakicic and his associates said.

They added that it has not yet been shown whether this weight loss will actually improve health-related outcomes.

This study was supported by the National Institutes of Health and the National Heart, Lung, and Blood Institute. Dr. Jakicic reported ties to Alere Wellbeing, Jenny Craig, Nestle Nutrition Institute, Beverage Institute for Health and Wellness, and Body Media. His associate reported ties to Allergan.