Age, period and cohort effects on body mass index in New Zealand, 1997–2038
Abstract Objective: To estimate the effects of age, period and birth cohort on observed trends, and to provide short‐ to medium‐term projections of population BMI in New Zealand. Methods: Data were obtained from New Zealand national health surveys covering the period 1997 to 2015 (n=76,294 individua...
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| Format: | Article |
| Language: | English |
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Elsevier
2018-08-01
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| Series: | Australian and New Zealand Journal of Public Health |
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| Online Access: | https://doi.org/10.1111/1753-6405.12804 |
| _version_ | 1797726935660363776 |
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| author | Ross Wilson J. Haxby Abbott |
| author_facet | Ross Wilson J. Haxby Abbott |
| author_sort | Ross Wilson |
| collection | DOAJ |
| description | Abstract Objective: To estimate the effects of age, period and birth cohort on observed trends, and to provide short‐ to medium‐term projections of population BMI in New Zealand. Methods: Data were obtained from New Zealand national health surveys covering the period 1997 to 2015 (n=76,294 individuals). A Hierarchical Age‐Period‐Cohort (HAPC) model and an Age‐Period model with interaction terms were specified for population groups defined by ethnicity and sex. Observed trends were extrapolated to estimate group‐specific BMI projections for the period 2015–2038; these were weighted by projected population sizes to calculate population‐wide BMI projections. Results: Population mean BMI increased from 26.4 kg/m2 (95%CI 26.2–26.5) in 1997 to 28.3 kg/m2 (95%CI 28.2–28.5) in 2015. Both models identified substantial, approximately linear, period trends behind this increase, with no significant cohort effects. Mean BMI was projected to reach 30.6 kg/m2 (95%CI 29.4–31.7; HAPC model) to 30.8 kg/m2 (95%CI 30.2–31.4; Age‐Period model) by 2038. Conclusions: BMI continues to increase in New Zealand. On current trends, population mean BMI will exceed 30 kg/m2 – the clinical cut‐off for obesity – by the early 2030s. Implications for public health: Unless prevented by comprehensive public health policy changes, increasing population obesity is likely to result in unfavourable economic and health impacts. |
| first_indexed | 2024-03-12T10:52:36Z |
| format | Article |
| id | doaj.art-7d5646f1ce094ff096c6b27785b7f7a7 |
| institution | Directory Open Access Journal |
| issn | 1326-0200 1753-6405 |
| language | English |
| last_indexed | 2024-03-12T10:52:36Z |
| publishDate | 2018-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Australian and New Zealand Journal of Public Health |
| spelling | doaj.art-7d5646f1ce094ff096c6b27785b7f7a72023-09-02T06:52:24ZengElsevierAustralian and New Zealand Journal of Public Health1326-02001753-64052018-08-0142439640210.1111/1753-6405.12804Age, period and cohort effects on body mass index in New Zealand, 1997–2038Ross Wilson0J. Haxby Abbott1Centre for Musculoskeletal Outcomes Research University of Otago New ZealandCentre for Musculoskeletal Outcomes Research University of Otago New ZealandAbstract Objective: To estimate the effects of age, period and birth cohort on observed trends, and to provide short‐ to medium‐term projections of population BMI in New Zealand. Methods: Data were obtained from New Zealand national health surveys covering the period 1997 to 2015 (n=76,294 individuals). A Hierarchical Age‐Period‐Cohort (HAPC) model and an Age‐Period model with interaction terms were specified for population groups defined by ethnicity and sex. Observed trends were extrapolated to estimate group‐specific BMI projections for the period 2015–2038; these were weighted by projected population sizes to calculate population‐wide BMI projections. Results: Population mean BMI increased from 26.4 kg/m2 (95%CI 26.2–26.5) in 1997 to 28.3 kg/m2 (95%CI 28.2–28.5) in 2015. Both models identified substantial, approximately linear, period trends behind this increase, with no significant cohort effects. Mean BMI was projected to reach 30.6 kg/m2 (95%CI 29.4–31.7; HAPC model) to 30.8 kg/m2 (95%CI 30.2–31.4; Age‐Period model) by 2038. Conclusions: BMI continues to increase in New Zealand. On current trends, population mean BMI will exceed 30 kg/m2 – the clinical cut‐off for obesity – by the early 2030s. Implications for public health: Unless prevented by comprehensive public health policy changes, increasing population obesity is likely to result in unfavourable economic and health impacts.https://doi.org/10.1111/1753-6405.12804obesityBMIAge‐Period‐Cohort analysis |
| spellingShingle | Ross Wilson J. Haxby Abbott Age, period and cohort effects on body mass index in New Zealand, 1997–2038 Australian and New Zealand Journal of Public Health obesity BMI Age‐Period‐Cohort analysis |
| title | Age, period and cohort effects on body mass index in New Zealand, 1997–2038 |
| title_full | Age, period and cohort effects on body mass index in New Zealand, 1997–2038 |
| title_fullStr | Age, period and cohort effects on body mass index in New Zealand, 1997–2038 |
| title_full_unstemmed | Age, period and cohort effects on body mass index in New Zealand, 1997–2038 |
| title_short | Age, period and cohort effects on body mass index in New Zealand, 1997–2038 |
| title_sort | age period and cohort effects on body mass index in new zealand 1997 2038 |
| topic | obesity BMI Age‐Period‐Cohort analysis |
| url | https://doi.org/10.1111/1753-6405.12804 |
| work_keys_str_mv | AT rosswilson ageperiodandcohorteffectsonbodymassindexinnewzealand19972038 AT jhaxbyabbott ageperiodandcohorteffectsonbodymassindexinnewzealand19972038 |