Combination of very low energy diets and pharmacotherapy in the treatment of obesity: meta-analysis of published data

Weight regain after total meal replacement very low-calorie diet program with and with-out anti-obesity medications

Background

Very low-calorie diets (VLCDs) employing total meal replacement (TMR) offer substantial short-term weight loss. Concurrently, anti-obesity medications (AOMs) have shown promise as adjunctive treatments when combined with VLCDs.

Aims

This study aimed to investigate the impact of adjuvant AOMs on weight loss and weight regain within a comprehensive lifestyle program.

Methods

This is a retrospective study of patients with obesity enrolled in VLCD/TMR programs,  specifically the OPTIFAST program.

Results

Data from 206 patients (68% women, mean age 52.39 ± 13.05 years, BMI 41.71 ± 7.04 kg/m2) were analyzed. Of these, 139 received no AOM (AOM-), while 67 received AOMs (AOM+). Total body weight loss percentages (TWL%) at 6 and 18 months were -17.87% ± 7.02 and -12.10% ± 11.56, respectively. There was no significant difference in 6-month weight loss between the AOM groups. However, the AOM + group exhibited lower weight regain (3.29 kg ± 10.19 vs. 7.61 kg ± 11.96; p = 0.006) and weight regain percentage (WR%) (31.5% ± 68.7 vs. 52.16% ± 64.4; p = 0.04) compared with the AOM- group.

Conclusion

The findings highlighted the potential of AOMs and VLCD/TMR as effective strategies for long-term weight management in individuals with obesity.

Effects on body weight, eating behavior, and quality of life of a low-energy diet combined with behavioral group treatment of persons with class II or III obesity: A 2-year pilot study

Objective

Obesity is associated with reduced health‐related quality of life (HRQoL). Outcomes of nonsurgical weight loss treatment on HRQoL are inconsistent and it is unclear how much weight reduction, or what type of treatment, is required for significant improvements. This study aimed to evaluate the effects of a lifestyle intervention program on weight, eating behaviors, and HRQoL, and to describe participants' experiences of treatment.

Methods

This 2‐year intervention trial in persons with class II or III obesity comprised a 3‐month liquid low‐energy diet (880 kcal/d) followed by a 3‐month reintroduction to regular foods, combined with behavioral group treatment.

Results

Fifty‐five participants (73% women) were included, mean (SD) age 43.2 (12.4) years, and mean body mass index 42.0 (6.0) kg/m². Mean weight loss at 6, 12, and 24 months was 18.9%, 13.7%, and 7.2%, respectively. Short‐ and long‐term effects on eating behavior were favorable. Twelve of 14 HRQoL domains were improved at 6 months, compared to eight domains at 12 months. After 24 months, 2 of 14 domains, physical and psychosocial functioning, were improved. The treatment program was well accepted by the participants.

Conclusions

Substantial weight loss after 6 months was associated with extensive improvements in HRQoL, comprising the physical, psychosocial, and mental domains. Significant weight regain was observed between 6 and 24 months follow‐up. Modest weight loss after 24 months was associated with moderate improvement in physical functioning and large improvement in psychosocial functioning. The effect on psychosocial functioning is most likely related to both weight loss and behavioral treatment.

Effectiveness and Characterization of Severely Energy-Restricted Diets in People with Class III Obesity: Systematic Review and Meta-Analysis

Severely energy-restricted diets are used in obesity management, but their efficacy in people with class III obesity (body mass index ≥40 kg/m2) is uncertain. The aims of this systematic review and meta-analysis were to determine the effectiveness and characteristics of severely energy-restricted diets in people with class III obesity. As there was a lack of publications reporting long-term dietary interventions and randomised controlled trial designs, our original publication inclusion criteria were broadened to include uncontrolled study designs and a higher upper limit of energy intake. Eligible publications reported studies including adults with class III obesity and that assessed a diet with daily energy intake ≤5000 kJ for ≥4 weeks. Among 572 unique publications from 4 databases, 11 were eligible and 10 were suitable for meta-analysis. Our original intention was to classify comparison arms into short-term (<6 months) and long-term (>1 year) interventions. Due to the lack of long-term data found, comparison arms were classified according to the commonalities in dietary intervention length among the included publications, namely dietary interventions of 4 weeks' duration and those of ≥6 weeks' duration. After a 4-week severely energy-restricted diet intervention, the pooled average weight loss was 9.81 (95% confidence interval 10.80, 8.83) kg, with a 95% prediction interval of 6.38 to 13.25 kg, representing a loss of approximately 4.1 to 8.6% of initial body weight. Diets ≥6 weeks' duration produced 25.78 (29.42, 22.15) kg pooled average weight loss, with a 95% prediction interval of 13.77 to 37.80 kg, representing approximately 10.2 to 28.0% weight loss. Daily dietary prescriptions ranged from 330 to 5000 kJ (mean ± standard deviation 2260 ± 1400 kJ), and had wide variations in macronutrient composition. The diets were administered mostly via liquid meal replacement products. While the included publications had a moderate risk of bias score, which may inflate reported weight loss outcomes, the published data to date suggest that severely energy-restricted diets, delivered via diets of varying composition, effectively produce clinically relevant weight loss (≥10% of initial body weight) when used for 6 weeks or more in people with class III obesity.

Efficacy of low- and very-low-energy diets in people with type 2 diabetes mellitus: A systematic review and meta-analysis of interventional studies

AIMS

To review systematically and quantify the weight loss achieved through low- (LEDs) and very-low-energy diets (VLEDs) in people with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Studies reporting the effects of diet-only interventions of up to 1600 kcal/d in people with T2DM were searched in MEDLINE, EMBASE and CINAHL up to July 2018. Changes in the primary (body weight and body mass index [BMI]) and secondary outcomes (glycated haemoglobin, blood lipids) according to energy restriction and duration of diet were modelled using restricted cubic splines.

RESULTS

Forty-four studies (3817 participants) were included. The overall quality of the evidence was moderate and limited to short-term interventions up to 4 months. Baseline mean weight and BMI were 92.1 kg and 36.6 kg/m² . VLEDs of 400 kcal/d led to 5.4% weight loss at 2 weeks, increasing to 17.9% at 3 months. More modest reductions of 7.3% were observed on LEDs of 1200 kcal/d and 2.0% on 1600 kcal/d after 3 months. No clear patterns emerged for secondary outcomes. Publication bias was significant for primary outcomes.

CONCLUSIONS

Through modelling, we were able to describe effective dietary deficit strategies to achieve weight reduction up to 4 months in people with T2DM. High-quality studies are required to further support clinical practice with evidence-based dietary interventions.