The Effect of Liquid Meal Replacements on Cardiometabolic Risk Factors in Overweight/Obese Individuals With Type 2 Diabetes: A Systematic Review and Meta-analysis of Randomized Controlled Trials
Article Figures & Tables
Figures
- Figure 1
Search summary.
- Figure 2
Summary of pooled effect estimates from RCTs investigating the effect of liquid meal replacements as part of a weight loss diet (intervention) compared with traditional low-calorie weight loss diets (comparator) on cardiometabolic risk factors. Pooled effect estimates are expressed as MDs with 95% CIs and, for visualization purposes, as SMDs with 95% CIs. SMDs are represented by the diamonds and 95% CIs by the line through the diamonds. Analyses were conducted using the generic inverse variance method with random effects models (at least 5 trials available) or fixed effects models (<5 trials available). Interstudy heterogeneity was tested by the Cochran Q statistic (χ2) at a significance level of PQ < 0.10. The GRADE approach was used to evaluate the certainty of the evidence. Evidence was graded as high, moderate, low, or very low quality. RCTs were graded as high-quality evidence by default and downgraded on the basis of risk of bias, inconsistency, indirectness, imprecision, and publication bias.
Tables
- Table 1
Summary of trial characteristics
Number of trials 9 Number of participants 961 Follow-up duration, weeks 24 (12–52) Design, number of trials Parallel 8 Crossover 1 Setting, number of trials Asia 4 North America 3 Europe 1 Australia 1 Participant characteristics at baseline Age, years 55 (51–62) Male: female (%)† 48: 52 BMI, kg/m2 30.5 (26.8–35.5) HbA1c, % 7.6 (6.5–8.8) HbA1c, mmol/mol 60 (48–73) Intervention characteristics Liquid meal replacement type, number of trials Glucerna SR 4 SlimFast 2 Medifast 1 Probiotec Formula WL 1 Microdiet 1 Liquid meal replacement dose, % E‡ 20 (13–47) Estimated total caloric intake, kcal/day§ 1,500 (1,195–1,659) Macronutrient composition, C: F: P (median)¶ 48: 30: 20 Comparator characteristics Comparator type, number of trials Food exchange system 4 Self-selected low-calorie foods 4 Diet book 1 Estimated total caloric intake, kcal/day§ 1,500 (1,350–1,737) Macronutrient composition, C: F: P (median)¶ 55: 25: 17 Dropout rate Intervention, % dropout 18 (1–43) Comparator, % dropout 20 (2–71) Funding source, number of trials** Agency 1 Industry 6 Agency and industry 1 Not reported 1 Data are median (range) unless otherwise indicated. % E, % energy; C, carbohydrate; F, fat; P, protein.
↵†Eight of nine trials provided data on sex.
↵‡If data were not provided, calculations were made under the assumption that an average individual consumes 2,000 kcal/day. For example, if participants consumed one serving of a 200-kcal liquid meal replacement per day and were recommended a caloric target by achievement of a 500-kcal deficit per day, then the dose was calculated as follows: ([200] / [2,000–500]) × 100% = ∼13% E.
↵§If data were not provided, calculations were made under the assumption that an average individual consumes 2,000 kcal/day. For example, if participants were recommended a caloric target by achieving a 500-kcal deficit per day, then the daily caloric intake was calculated as follows: 2,000 – 500 = 1,500 kcal/day.
↵¶Four of nine trials provided data for the intervention group and six of nine trials provided data for the comparator group from which macronutrient composition could be estimated. End-of-study values measuring energy from carbohydrates, fat, and protein were reported only if the study did not report or design diets to have a planned macronutrient composition.
↵**Agency funding is that from government, university, or not-for-profit sources. Industry funding is that from trade organizations that obtain revenue from the sale of products.
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