International Journal of Obesity (1998) 22, 190±192
ß 1998 Stockton Press All rights reserved 0307±0565/98 $12.00
Intermittent vs continuous VLCD therapy in obesity treatment
Obesity Unit, Huddinge University Hospital, Huddinge, Sweden
The role of intermittent very low calorie diet (VLCD) in obesity treatment has received little attention. Since such programs can be carried out with limited medical resources, they may offer an additional therapeutic tool. In two studies the effects of 420 or 530 kcal of Nutrilett1 given daily to 40 and 61 patients [body mass index (BMI)
39.2 Æ 5.1 kg=m2 and 39.0 Æ 5.0 kg=m2, respectively], either continuously for six weeks or for three periods of two weeks with four weeks maintenance interval, were compared. Attrition and weight loss was similar in both groups after 14 and 26 weeks. Intermittent VLCD treatment seems to result in long term weight losses and compliance similar to those obtained by more continuous VLCD therapy. For some individuals less side effects would favour intermittent treatment, for others motivational factors support a more continuous VLCD treatment regimen.
Keywords: compliance; intermittent therapy; obesity; very low calorie diet
16 kg were lost during the ®rst period, only 1.4 kg was lost in the second.
We decided to study how a strategy of intermittent
VLCD treatment under two-week conditions would compare with a more conventional longterm VLCD treatment regimen, in a pilot study of obese patients at the obesity unit. Our hypothesis was, that intermittent
VLCD therapy might result in similar or improved weight loss and thus prove a worthwhile treatment option.
Very low calorie diets (VLCD) in combination with the long-term combined behaviour modi®cation program developed at our Obesity Unit can result in marked initial weight loss followed by a sustained weight maintenance for time periods up to two years.1±5 However, responsible use of VLCD for time periods exceeding two weeks requires medical supervision, as has been pointed out by Wadden et al.6
In many situations, lack of quali®ed manpower resources limit the use of long term VLCD programs.
In these instances, it seems reasonable to develop
VLCD program alternatives which do not require safety precautions such as frequent medical supervision, ECG recordings, electrolyte measurements etc.
The Swedish Food Agency has recommended that
VLCD products may be used for two weeks without medical supervision. Such information is also given on the VLCD packages which are for sale on the open market.
However, little information is available concerning the long term consequences of intermittent VLCD treatment. Wing et al7 studied 93 diabetic patients, who were treated with VLCD for three months, then were kept on a maintenance program for another three months before being given VLCD again for an additional three months. The authors hypothesized that signi®cant weight loss should occur during the second
VLCD period, but the evaluation showed that whereas
Patients and methods
Patients for this study were recruited from the existing waiting list of the Obesity Unit. Patients were included in the trial on two different occasions, one year apart and randomly allocated to either six weeks of continuous treatment with a standard commercially available VLCD or the same total duration of VLCD therapy, but divided into three periods of two weeks, separated by a monthly interval of a regular balanced low calorie diet, according to the standard dietary protocol of the Obesity Unit.1 During the course of the study, the VLCD available changed slightly, but only in energy content, from 420 kcal=d to 530 kcal=d.
Thus the study comprised two different patient groups, recruited from the waiting list with an interval of one year. A total of 40 women (mean age 36 y, range 21±60 y) taken in turn from the waiting list, were recruited to the ®rst 420 kcal group (Nutrilett,
Nycomed, Oslo). Inclusion criteria were a body mass index (BMI) exceeding 30 kg=m2, stable living conditions as regards occupation, travel, distance from the hospital (making frequent contacts with the Unit possible), medical indications justifying VLCD treat-
Correspondence: Stephan RoÈ ssner, Obesity Unit, Huddinge
Hospital, S 141 86 Huddinge, Sweden. fax: 46 8 774 9962, e-mail: email@example.com
Received 15 April 1997; revised 8 September 1997; accepted
9 October 1997 Short intermittent VLCD therapy
Table 1 Weight loss (kg) in obese subjects on Nutrilett very low calorie diet (VLCD) (420 or 530 kcal=d) either on continuous (166 weeks) or intermittent (362 weeks) treatment. Mean Æ s.d. shown.
420 kcal=d (women only) Men Women
Week Continuous (n) Intermittent (n) Continuous (n) Intermittent (n) Continuous (n) Intermittent (n)
0105.6 Æ 10.5 (20)
14 92.6 Æ 10.9 (16)
26 95.5 Æ 11.1 (16)
106.2 Æ 14.2 (20)
90.5 Æ 13.3 (18)
92.1 Æ 14.6 (17)
127.4 Æ 9.6 (10)
108.2 Æ 11.1 (7)
107.7 Æ 12.9 (10)
135.0 Æ 21.6 (10)
107.7 Æ 15.3 (8)
108.8 Æ 24.4 (9)
107.7 Æ 17.6 (22)
94.9 Æ 12.0 (18)
94.9 Æ 12.6 (16)
114.5 Æ 13.0 (19)
99.6 Æ 16.3 (16)
99.0 Æ 16.8 (13) ment and no other concomitant diseases (such as standard cardiological, hepatic or renal complications) that made VLCD an inappropriate treatment modality.6,8 The second Nutrilett group, 530 kcal=d, comprised 61 patients (41 women and 20 men, mean age for all, 41 y, range 22±69 y) with identical inclusion criteria.
Quantitative data were summarised using number of observations, mean, standard deviation, minimum and maximum values. Analysis of variance (ANOVA) at different time was used to analyse weight reduction. P values 0.05 were considered statistically signi®cant. The statistical analysis was performed using
After extensive education in group sessions the patients were randomly allocated to either treatment group and monitored by the same nurse throughout the program. The core protocol was based on the long Hospital Ethics Committee. term combined behavioral modi®cation program, which forms the main framework for all treatment programs at the Obesity Unit.9 Details of the program design in combination with a VLCD are described elsewhere.5 Patients were seen on a weekly basis up to week 14, when the groups had completed a total of six weeks of VLCD treatment, although in different regimens. After week 14, patients were invited to biweekly weigh-in sessions, with all patients in the program coming in at weeks 20±26. Patients who did not return for weigh-ins were reinvited by telephone once or twice, but not approached further. Compliance during VLCD periods was checked with multiple urinary ketone body measurements. Side effects and subjective feelings were checked by lists and recorded on every visit to the nurse. The concomitant dietary program has been previously described.9 After a VLCD period, a short conventional refeeding program was introduced, lasting for about a week. The diet was a balanced hypocaloric standard program used at the Obesity Unit, giving approximately 1600 kcal=d and focusing on regular meal times and low fat cooking.
Modest exercise was encouraged, but no formal activities were scheduled. In addition to the trained nurse running the main part of the program, a dietitian and also a physiotherapist instructed the subjects during some sessions. The dietitian provided dietary guidelines for a balanced diet and gave practical advice for the refeeding program after each VLCD period. The physiotherapist gave standard advice about simple, regular physical activity, but did not include more rigorous exercise programmes. A physician was available for consultation upon request, and for occasional lectures and group support, but was not otherwise routinely involved in the program.
All patients gave their informed consent to participate and the protocol was approved by the Karolinska
The weight loss results are summarised in the Table 1.
Before treatment the mean initial BMI values in all groups were similar.
In the continuous therapy group, the mean initial
BMI was 39.2 Æ 5.1 kg=m2, in the intermittent therapy group 38.3 Æ 4.2 kg=m2. After 14 weeks as well as after 26 weeks the attrition and the mean weight loss in both groups were similar. The weight losses during the three periods are shown in Table 2. The patients in the intermittent therapy groups did not increase in body weight in the two dietary periods between the VLCD treatment weeks.
530 kcal/d. In the continuous therapy group, the mean initial BMI was 39.0 Æ 5.2 kg=m2, in the intermittent group 41.1 Æ 5.3 kg=m2 for the genders combined.
After 14 and 26 weeks, attrition rates were similar for both men and women in both treatment groups. In men, the mean weight losses after 14 and 26 weeks with both treatment regimens was similar. Women lost slightly more weight on the continuous, compared to intermittent, therapy program. Although the initial
Table 2 Weight loss (kg) during the intermittent very low calorie diet (VLCD) treatment two week periods
0^2 weeks 6^8 weeks 12^14 weeks
420 kcal=d 530 kcal=d women only 6.0 Æ 2.0 4.6 Æ 1.6 3.4 Æ 1.9
men 5.6 Æ 2.6 6.6 Æ 2.1 2.1 Æ 4.6
women 4.1 Æ 1.0 4.3 Æ 2.1 3.6 Æ 2.2
Patients were instructed to adhere to the same smoking habits throughout the trial. Short intermittent VLCD therapy
192 body weights did not differ signi®cantly (P 0.17),
2.1 kg more was lost after 14 weeks and 2.7 kg more was lost after 26 weeks.
In the intermittent therapy program the weight losses during the three VLCD periods are shown in
Table 2. There were no statistically signi®cant differences in weight loss between the three periods in either gender.
In all groups and with both Nutrilett preparations, side effects were mild and transient. In general, ome patients complained of muscle fatigue and hair loss, but since these problems appeared at different times and with varying intensity, no systematic difference whatsoever was found between the groups. In no case was withdrawal of VLCD treatment required. subgroups even better. The weight loss pattern was similar in the two different Nutrilett groups, with the weight loss achieved after 14 weeks being maintained at week 26 and with similar compliance. Among the advantages reported by the patients in the intermittent treatment groups, was the fact that two weeks with
VLCD was an acceptable duration that did not require too much in the way of life style changes, and that less muscle fatigue and no hair loss occurred. Some patients however found it dif®cult to embark again on the VLCD program and would rather have continued, once the anorexia associated with an ongoing
VLCD program had manifested itself and made it easy to adhere to the VLCD regimen.
Intermittent VLCD treatment has received very little attention in the literature, and many physicians have the impression that regain inevitably occurs after each
VLCD treatment period. This may not necessarily be the case. This study demonstrates that repeated intermittent treatment with VLCD for two weeks (the allowed Swedish unsupervised duration for use without medical support) results in a weight loss at least comparable to the same duration as part of continuous VLCD treatment and with a similar degree of compliance.
The weight losses obtained in this VLCD trial are similar to our data obtained with similar treatment duration and similar patient categories.1±5 The patients studied were taken from the clinical waiting list; for practical reasons a number of women waiting for treatment were allocated to the ®rst program, whereas the second program consisted of subjects from both genders. The main results are in principle similar and no gender speci®c differences in response to VLCD are to be expected, although the men on 530 kcal=d were heavier and lost more. Since the routinely available commercial Nutrilett preparation was used, the second treatment group received a slightly different preparation. It is unlikely that these minor differences in energy content affected the outcome. In previous studies we found no signi®cant weight loss differences between Nutrilett preparations with an energy content varying between 430 kcal=d and even up to
880 kcal=d.5 There is no obvious explanation for the fact that in one subgroup (women on 530 kcal=d continuous therapy) weight loss was lower; reverse trends were seen for women in the 420 kcal=d group and for men.
As in almost every study of this kind, the weight loss in all the different groups are smaller than could be calculated on a theoretical basis. This certainly suggests that compliance in spite of all efforts was far from complete.
The study supports the results from our previous work that VLCD programs of up to six weeks duration can be safely run by a trained nurse with limited involvement of a physician.1,5 Signi®cant weight loss occurs during each two weeks of VLCD therapy. This
®nding contrasts with the results described by Wing et al,6 where patients during their second VLCD period, although lasting for as long as three months, lost an insigni®cant amount of weight in comparison to the ®rst period.
The skilful and dedicated work of the research nurses
Eva-Lena Fredriksson and Lena MannstroÈm in long term motivating, treating and monitoring the patients, is gratefully acknowledged. Supported by Karolinska
Institute research funds and Nycomed, Oslo.
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Overall, the intermittent treatment patients did as well as those on continuous VLCD treatment, in some