SEARCH

SEARCH BY CITATION

Keywords:

  • epidemiology;
  • national survey;
  • educational level;
  • geographic distribution;
  • trends

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Research Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

Objective: To assess overweight and obesity trends in the Portuguese population.

Research Methods and Procedures: National Health Surveys, conducted in 1995–6 (17, 989 men; 20, 249 women) and 1998–9 (17, 923 men; 20, 302 women), were used.

Results: In men, the prevalence of overweight and obesity increased from 39.9% (95% CI: 39.2 to 40.6) and 10.3% (95% CI: 9.9 to 10.7), respectively, in 1995–6, to 42.5% (95% CI: 41.8 to 43.2) and 11.5% (95% CI: 11.0 to 12.0), respectively, in 1998–9. In women, prevalence of obesity increased from 12.7% (95% CI: 12.2 to 13.2) in 1995–6 to 14.2% (95% CI: 13.7 to 14.6) in 1998–9, whereas the prevalence of overweight remained stable: 32.2% (95% CI: 31.6 to 32.9) in 1995–6 and 32.3% (95% CI: 31.6 to 32.9) in 1998–9. In men, prevalence of overweight and obesity were higher among former smokers and educational group of 6 to 12 years, and prevalence of obesity was higher in the Lisbon region. In women, prevalence of overweight and obesity were higher among never smokers, and prevalence of obesity was higher among educational group of −6 years. Prevalence of obesity was higher in the Alentejo region, and overweight was higher in the Center region. Finally, prevalence of obesity increased in both sexes for all strata studied (age, smoking status, educational level, and geographic region), whereas prevalence of overweight increased only in men.

Discussion: In Portugal, overweight and obesity levels are related to sociodemographic factors; the increase in obesity levels stresses the need for preventive measures.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Research Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

Obesity is a disease and a major risk factor for chronic disorders, and its prevalence has been steadily increasing worldwide. Although the prevalence of obesity has been well assessed in most industrialized countries, little is known regarding its true prevalence in Portugal, a South European country where obesity is supposed to account for ∼3.5% of all health expenditures, 61% of which are due to cardiovascular disease. Thus, we used the data from the 1998–9 National Health Survey to assess the prevalence of obesity in the Portuguese population.

Research Methods and Procedures

  1. Top of page
  2. Abstract
  3. Introduction
  4. Research Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

The Portuguese National Health Surveys

National Health Surveys were conducted between May 1995 and April 1996 (1995–6) and between October 1998 and September 1999 (1998–9). The sampling frame included all subjects living in individual housing during that period. (Collective housing such as hospitals, prisons, military barracks, or retirement houses were excluded.) The sample was considered representative of the main regions of continental Portugal (North, Center, Lisbon region, Alentejo, and Algarve). The sampling unit was the house, and data were derived from the population and housing census of 1991. Two strata were defined: the freguesias (corresponding to counties) and, within the freguesias, geographically defined units of ∼300 lodgings. All subjects living in the sampling unit (house) were surveyed. Data were collected by trained staff according to a standardized protocol (1), and quality control was maintained by reapplying (by a different interviewer) the same questionnaire to 10% of the initial sample (2). Overall participation rate was 88% in 1995–6 and 82% in 1998–9.

In 1995–6, 49, 718 subjects were surveyed, of whom 38, 238 (17, 989 men and 20, 249 women) were ≥20 years old and had reported height and weight measurements; the corresponding figures for 1998–9 were 48, 606 and 38, 225 subjects, respectively (17, 923 men and 20, 320 women).

Data Collection

All data were obtained by interview. Height and weight were self-reported; overweight was defined as a BMI ≥25 and <30 kg/m2; obesity was defined as a BMI ≥30 kg/m2. Educational level was assessed by the number of years spent in school and classified into three groups: ≤6 years (primary school; −6); >6 to 12 years (secondary school; 6 to 12); and >12 years (university level; 12+); smoking was assessed in three categories (current, previous, never).

Statistical Analysis

Statistical analysis was conducted using SAS version 8.0 and Enterprise Guide version 2.05 (SAS Institute, Cary, NC). Qualitative variables were expressed as percentage (95% CI); quantitative variables were expressed as mean ± SD.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Research Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

In both sexes, BMI increased slightly between the 1995–6 and the 1998–9 survey (men: 25.5 ± 3.5 to 25.8 ± 3.7 kg/m2; women: 25.2 ± 4.4 to 25.4 ± 4.5 kg/m2), whereas no differences in BMI were found for age (data not shown); also, the number of subjects with a university degree increased, and the number of subjects with primary education decreased (data not shown). In men, the prevalence of former smokers increased from 27.5% to 29.1%, whereas the prevalence of current smokers remained relatively stable (30.7% and 30.9%); conversely, in women, the prevalence of both current and former smokers increased (6.6% to 8.2% and 4.3% to 6.0%, respectively).

In men, the overall prevalence of overweight and obesity increased from 39.9% (95% CI: 39.2 to 40.6) and 10.3% (95% CI: 9.9 to 10.7), respectively, in 1995–6, to 42.5% (95% CI: 41.8 to 43.2) and 11.5% (95% CI: 11.0 to 12.0), respectively, in 1998–9. In women, the overall prevalence of obesity increased from 12.7% (95% CI: 12.2 to 13.2) in 1995–6 to 14.2% (95% CI: 13.7 to 14.6) in 1998–9, whereas the prevalence of overweight remained relatively stable: 32.2% (95% CI: 31.6 to 32.9) in 1995–6 to 32.3% (95% CI: 31.6 to 32.9) in 1998–9.

In both sexes, the prevalence of overweight and obesity increased with age; for the 1998–9 survey, it increased in men from 27.4% (95% CI: 25.9 to 28.9) and 4.4% (95% CI: 3.7 to 5.1), respectively, in the 20- to 29-year age group to 49.3% (95% CI: 47.5 to 51.1) and 15.0% (95% CI: 13.7 to 16.3), respectively, in the 50- to 59-year age group. In women, it increased from 14.3% (95% CI: 13.0 to 15.5) and 3.8%, (95% CI: 3.1 to 4.4), respectively, in the 20- to 29-year age group to 38.9% (95% CI: 36.8 to 40.9) and 21.3% (95% CI: 19.6 to 23.0), respectively, in the 50- to 59-year age group (Figure 1).

image

Figure 1. : Trends in the prevalence of overweight (▴) and obesity (▪) according to age group for men (A) and women (B). Results are expressed in percentage. Dotted lines, 1995–6; full lines, 1998–9.

Download figure to PowerPoint

The trends in the prevalence of overweight and obesity according to different sociodemographic characteristics and sex are summarized in Table 1. In men, the prevalence of overweight and obesity were higher among former smokers and in the educational group of 6 to 12, and prevalence of obesity was higher in the Lisbon region. In women, the prevalence of overweight and obesity were higher in the never smokers, and prevalence of obesity was higher in the educational group of −6; the prevalence of obesity was higher in the Alentejo region, and the prevalence of overweight was higher in the Center region. Between the 1995–6 and the 1998–9 surveys, the prevalence of obesity increased in both sexes for practically all strata studied, whereas the prevalence of overweight increased in men, but a relative stabilization was noted in women.

Table 1. . Trends in the prevalence of overweight and obesity according to different parameters, by sex
 MenWomen
 OverweightObesityOverweightObesity
 1995–61998–91995–61998–91995–61998–91995–61998–9
  1. Results are expressed as percentage of subjects (95% CI).

Smoking        
Current33.9 (32.7 to 35.2)36.2 (34.9 to 37.5)6.6 (6.0 to 7.3)7.5 (6.8 to 8.2)15.6 (13.6 to 17.5)18.4 (16.5 to 20.2)5.2 (4.0 to 6.4)5.2 (4.2 to 6.3)
Former44.8 (43.4 to 46.2)47.3 (45.9 to 48.6)13.2 (12.3 to 14.2)15.0 (14.0 to 15.9)21.6 (18.8 to 24.3)24.4 (22.0 to 26.8)8.1 (6.3 to 10.0)9.9 (8.2 to 11.6)
Never41.1 (40.0 to 42.2)43.9 (42.7 to 45.0)11.1 (10.3 to 11.8)12.1 (11.3 to 12.8)34.0 (33.3 to 34.7)34.2 (33.5 to 34.9)13.5 (13.0 to 14.0)15.3 (14.8 to 15.8)
Educational level        
−633.2 (31.7 to 34.7)35.8 (34.1 to 37.5)9.4 (8.5 to 10.3)9.8 (8.8 to 10.9)31.8 (30.6 to 32.9)32.3 (31.0 to 33.5)14.7 (13.8 to 15.6)16.0 (15.1 to 17.0)
6 to 1242.5 (41.6 to 43.4)45.0 (44.1 to 45.8)11.3 (10.7 to 11.8)12.9 (12.3 to 13.4)35.4 (34.5 to 36.2)35.6 (34.7 to 36.4)13.3 (12.6 to 13.9)15.7 (15.0 to 16.3)
12+36.7 (34.6 to 38.8)38.5 (36.6 to 40.4)6.0 (5.0 to 7.1)6.8 (5.8 to 7.7)16.6 (15.0 to 18.2)17.9 (16.5 to 19.4)4.0 (3.1 to 4.8)4.1 (3.3 to 4.8)
Region        
North40.8 (39.4 to 42.2)42.3 (40.5 to 44.1)8.8 (8.0 to 9.6)10.6 (9.5 to 11.7)32.2 (31.0 to 33.4)32.4 (31.2 to 33.6)10.9 (10.1 to 11.7)13.1 (12.3 to 14.0)
Center40.1 (38.5 to 41.7)46.4 (44.6 to 48.2)11.0 (9.9 to 12.0)12.0 (10.9 to 13.2)31.9 (30.5 to 33.3)33.6 (32.1 to 35.0)11.2 (10.2 to 12.1)13.6 (12.6 to 14.7)
Lisbon40.6 (39.2 to 41.9)43.0 (41.2 to 44.7)11.8 (10.9 to 12.6)12.4 (11.3 to 13.6)32.1 (30.8 to 33.3)32.6 (31.3 to 33.8)15.0 (14.0 to 15.9)15.6 (14.6 to 16.5)
Alentejo36.3 (34.4 to 38.2)40.9 (39.1 to 42.6)11.1 (9.9 to 12.4)12.2 (11.0 to 13.3)34.2 (32.4 to 36.0)31.0 (29.2 to 32.8)15.2 (13.8 to 16.6)17.3 (15.8 to 18.7)
Algarve40.2 (38.0 to 42.3)37.3 (35.6 to 39.0)8.0 (6.8 to 9.1)10.0 (8.9 to 11.1)30.8 (28.8 to 32.8)30.5 (28.6 to 32.3)11.4 (10.0 to 12.7)11.0 (9.7 to 12.3)

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Research Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

To our knowledge, this is the first study to assess the trends in overweight and obesity using representative samples of the Portuguese population. Our data indicate that, in 1998–9, the overall prevalence of overweight and obesity in the Portuguese population was almost 50% (37.0% for overweight and 12.9% for obesity), slightly higher than previously reported in smaller studies conducted in Portugal (3), Spain (4), and France (5), but lower than in the United States (6).

In women, the prevalence of obesity was higher and the prevalence of overweight was lower than in men, a feature already reported by others (6, 7) but not all (4). Possible explanations might be the lower reported daily physical activity or the lower prevalence of smoking among women, which would increase the prevalence of obesity in women relative to men, although other factors such as menopause and differences in dietary intake cannot be ruled out.

Prevalence of overweight and obesity increased with age, to reach a maximum between 50 and 59 years, in agreement with a study conducted in Spain (8). However, the prevalence of obesity in our sample was slightly lower than that reported for the same age group in other southern European countries (9). A possible explanation might be that, in our study, height and weight were self-reported, leading to an underestimation of the prevalence of overweight and obesity (10). Interestingly, decreasing height by 1 cm and increasing weight by 1 kg would lead to an estimated overall prevalence of overweight and obesity in 1998–9 of 46.2% and 15.8% in men, respectively, and 35.5% and 17.8% in women, respectively, which are closer to those reported in the European Prospective Investigation into Cancer and Nutrition study (9).

In both sexes, prevalence of overweight and obesity differed according to smoking status and educational level, a feature already described (11, 12, 13). Possible reasons might be differences in age (women smokers are younger), physical activity, and dietary patterns. Contrary to other studies (7), no clear North-South gradient was found; rather, overweight and obesity levels were higher in the most industrialized (Lisbon) and in the most rural (Alentejo) regions. Although environmental factors such as better transportation or a more sedentary way of life might partly explain these findings, further studies are needed to assess this point.

The prevalence of obesity increased between 1995–6 and 1998–9, a finding in agreement with several studies (4, 6, 14) but not all (7). Conversely, the prevalence of overweight increased in men and remained stable in women; this relative stabilization of the prevalence of overweight has already been reported in other studies (6, 7). Several factors can account for the increase in the prevalence of overweight and obesity: smoking cessation (15), reduced physical activity (16), or inadequate dietary intake (17), but the exact contribution of each factor awaits further study.

The prevalence of obesity increased in both sexes for all strata studied (age, smoking status, educational level, and geographic region). Although the increase was more pronounced in subjects with a primary or secondary school level compared with those with a university degree, a finding already reported (18), we do believe that preventive measures should be issued for the overall Portuguese population group, rather than for specific groups. Furthermore, because obesity accounts for ∼3.5% of the Portuguese health expenditures (19), the economical impact of a further increase in overweight and obesity levels can be enormous.

In summary, our data indicate that the prevalence of overweight and obesity are related to age, educational level, smoking status, geographic region, and physical activity levels in the Portuguese population. Also, the increase in the prevalence of obesity in both sexes, and of overweight in men, stresses the need for preventive measures.

Acknowledgement

  1. Top of page
  2. Abstract
  3. Introduction
  4. Research Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References

We thank the Observatório Nacional de Saúde for providing the data and Maria Ermelinda Camilo who thoroughly revised the manuscript. The Unidade de Nutrição e Metabolismo of the Instituto de Medicina Molecular is partially funded by a grant from the Fundação para a Ciênciaea Tecnologia (RUN 437).

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Research Methods and Procedures
  5. Results
  6. Discussion
  7. Acknowledgement
  8. References
  • 1
    Ministério da Saúde. (1998) Inquérito Nacional de Saúde—Manual do Entrevistador. Portuguese Ministry of Health, Observatório Nacional de Saúde, Instituto Nacional de Saúde, Dr. Ricardo Jorge: Lisboa, Portugal.
  • 2
    Ministério da Saúde (2001) Inquérito Nacional de Saúde—Nota Metodológica. Portuguese Ministry of Health, Observatório Nacional de Saúde, Instituto Nacional de Saúde, Dr. Ricardo Jorge: Lisboa, Portugal.
  • 3
    Simões, J. A., Gama, M. E., Contente, CB. (2000) Prevalência de factores de risco cardiovascular numa população rural com idade entre os 25 e os 44 anos. Rev Port Cardiol. 19: 693703.
  • 4
    Rodríguez-Artalejo, F., López García, E., Gutiérrez-Fisac, J. L., Banegas, Banegas Jr., Lafuente Urdinguio P. J., Rojas, V. Domínguez (2002) Changes in the prevalence of overweight and obesity and their risk factors in Spain, 1987–1997. Prev Med. 34: 7281.
  • 5
    Marques-Vidal, P., Ruidavets, J. B., Cambou, J. P., Ferrières, J. (2002) Trends in overweight and obesity in middle-aged subjects from southwestern France, 1985–1997. Int J Obes Relat Metab Disord. 26: 732734.
  • 6
    Flegal, K. M., Carroll, M. D., Kuczmarski, R. J., Johnson, CL. (1998) Overweight and obesity in the United States: prevalence and trends, 1960–1994. Int J Obes Relat Metab Disord. 22: 3947.
  • 7
    Marques-Vidal, P., Ruidavets, J. B., Amouyel, P., et al (2004) Change in cardiovascular risk factors in France, 1985–1997. Eur J Epidemiol. 19: 2532.
  • 8
    Gutiérrez-Fisac, J. L., Banegas, Banegas Jr., Rodríguez-Artalejo, F., Regidor, E. (2000) Increasing prevalence of overweight and obesity among Spanish adults, 1987–1993. Int J Obes Relat Metab Disord. 24: 16771682.
  • 9
    Haftenberger, M., Lahmann, P. H., Panico, S., et al (2002) Overweight, obesity and fat distribution in 50- to 64-year-old participants in the European Prospective Investigation into Cancer and Nutrition (EPIC). Public Health Nutr. 5: 11471162.
  • 10
    Paccaud, F., Wietlisbach, V., Rickenbach, M. (2001) Body mass index: comparing mean values and prevalence rates from telephone and examination surveys. Rev Epidémiol Santé Publ. 49: 3340.
  • 11
    Hu, G., Pekkarinen, H., Hanninen, O., Tian, H., Jin, R. (2002) Comparison of dietary and non-dietary risk factors in overweight and normal-weight Chinese adults. Br J Nutr. 88: 9197.
  • 12
    Gutiérrez-Fisac, J. L., Regidor, E., Banegas, Banegas Jr., Rodriguez Artalejo F. (2002) The size of obesity differences associated with educational level in Spain, 1987 and 1995/97. J Epidemiol Commun Health. 56: 457460.
  • 13
    de Castro, J. Jácome, Baptista, F., Aleixo, Dias J., Lacerda Nobre E., Camilo Alves A., Galvão, Teles A. (2000) Relação entre a obesidadeeo nível educacional nos mancebos portugueses do sexo masculino em 1990. Acta Med Port. 13: 16.
  • 14
    de Castro, J. Jácome, Aleixo Dias J., Baptista, F., Garcia, Costa J., Galvão-Teles, A., Camilo-Alves, A. (1998) Secular trends of weight, height and obesity in cohorts of young Portuguese males in the district of Lisbon: 1960–1990. Eur J Epidemiol. 14: 299303.
  • 15
    Flegal, K. M., Troiano, R. P., Pamuk, E. R., Kuczmarski, R. J., Campbell, SM. (1995) The influence of smoking cessation on the prevalence of overweight in the United States. N Engl J Med. 333: 11651170.
  • 16
    Prentice, A. M., Jebb, SA. (1995) Obesity in Britain: gluttony or sloth? Br Med J. 311: 437439.
  • 17
    Spencer, E. A., Appleby, P. N., Davey, G. K., Key, TJ. (2003) Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans. Int J Obes Relat Metab Disord. 27: 728734.
  • 18
    Gutiérrez-Fisac, J. L., Regidor, E., Rodriguez, C. (1996) Trends in obesity differences by educational level in Spain. J Clin Epidemiol. 49: 351354.
  • 19
    Pereira J, Mateus C, Amaral MJ, eds. (1999). Custo da Obesidade em Portugal. Associação Portuguesa de Economia da Saúde: Lisbon, Portugal.