Table 1

Summary of trial characteristics

Number of trials9
Number of participants961
Follow-up duration, weeks24 (12–52)
Design, number of trials
 Parallel8
 Crossover1
Setting, number of trials
 Asia4
 North America3
 Europe1
 Australia1
Participant characteristics at baseline
Age, years55 (51–62)
Male: female (%)48: 52
BMI, kg/m230.5 (26.8–35.5)
HbA1c, %7.6 (6.5–8.8)
HbA1c, mmol/mol60 (48–73)
Intervention characteristics
 Liquid meal replacement type, number of trials
  Glucerna SR4
  SlimFast2
  Medifast1
  Probiotec Formula WL1
  Microdiet1
 Liquid meal replacement dose, % E20 (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 system4
  Self-selected low-calorie foods4
  Diet book1
 Estimated total caloric intake, kcal/day§1,500 (1,350–1,737)
 Macronutrient composition, C: F: P (median)55: 25: 17
Dropout rate
 Intervention, % dropout18 (1–43)
 Comparator, % dropout20 (2–71)
Funding source, number of trials**
 Agency1
 Industry6
 Agency and industry1
 Not reported1
  • 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.