Effectiveness of dietary interventions among adults of retirement age: a systematic review and meta-analysis of randomized controlled trials

Abstract

Background: Retirement from work involves significant lifestyle changes and may represent an opportunity to promote healthier eating patterns in later life. However, the effectiveness of dietary interventions during this period has not been evaluated.

Methods: We undertook a systematic review of dietary interventions among adults of retirement transition age (54 to 70 years). Twelve electronic databases were searched for randomized controlled trials evaluating the promotion of a healthy dietary pattern, or its constituent food groups, with three or more months of follow-up and reporting intake of specific food groups. Random-effects models were used to determine the pooled effect sizes. Subgroup analysis and meta-regression were used to assess sources of heterogeneity.

Results: Out of 9,048 publications identified, 68 publications reporting 24 studies fulfilled inclusion criteria. Twenty-two studies, characterized by predominantly overweight and obese participants, were included in the meta-analysis. Overall, interventions increased fruit and vegetable (F&V) intake by 87.5 g/day (P <0.00001), with similar results in the short-to-medium (that is, 4 to 12 months; 85.6 g/day) and long-term (that is, 13 to 58 months; 87.0 g/day) and for body mass index (BMI) stratification. Interventions produced slightly higher intakes of fruit (mean 54.0 g/day) than of vegetables (mean 44.6 g/day), and significant increases in fish (7 g/day, P = 0.03) and decreases in meat intake (9 g/day, P <0.00001).

Conclusions: Increases in F&V intakes were positively associated with the number of participant intervention contacts. Dietary interventions delivered during the retirement transition are therefore effective, sustainable in the longer term and likely to be of public health significance.

Figure 1

Study selection flow diagram (PRISMA template).

Figure 2

Funnel plot of randomized controlled trials assessing fruit and vegetable intakes. Egger’s regression test P = 0.394.

Figure 3

Randomized controlled trials reporting overall fruit and vegetable intakes among people of retirement age.

Figure 4

Randomized controlled trials reporting fruit intake among people of retirement age.

Figure 5

Randomized controlled trials reporting vegetable intake among people of retirement age.

Figure 6

Meta-regression analysis of effects of number of contacts during interventions on fruit and vegetable intakes. Slope = 3.80, Q = 36.93, d.f. = 1, P <0.0001. The circle size reflects the weight that a study obtained in the meta-regression.