The Functional Significance of Low Body Mass Index (IDECG, 1992, 203 p.): Body mass index values in the Cuban adult population: Methods

The Functional Significance of Low Body Mass Index (IDECG, 1992, 203 p.)

(introduction...)

Foreword

Introduction: the challenge of adult chronic energy deficiency

(introduction...)

Introduction

Indices of chronic energy deficiency in adults

The FAO initiative

A simplification in the approach to adult CED

The use of BMI alone in CED diagnosis

Challenge to come

The functional significance of modest reductions in BMI

Applications of BMI monitoring

Causes of CED

Conclusions

References

Discussion

Population differences in body composition in relation to the body mass index

(introduction...)

Introduction

BMI and body composition: theoretical considerations

Interpreting BMI in developed countries

Interpreting BMI in developing countries

Body composition of Third World populations and BMI

The effect of shape

References

Discussion

Body mass index: its relationship to basal metabolic rates and energy requirements

(introduction...)

Introduction

Nutritional anthropometric indices and their relationship to BMR

Do population groups in developing countries in the tropics have lower BMRs?

Low BMIs, BMRs and energy requirements

Changes in body weights and stature and their influence on BMI and energy requirements

References

Discussion

Low body mass index, physical work capacity and physical activity levels

(introduction...)

Introduction

Work capacity or 'stress'

Low work capacity in a normal population

Relevance of form of activity

A theoretical analysis of effect; of BMI on activity

Proposed minimum level of BMI to effect work capacity and activity

BMI and the nature of work and activity

Conclusion

References

Discussion

Body mass index and economic productivity

(introduction...)

Introduction

Evidence of nutrition/productivity links

Women's BMI and productivity

Summary and conclusions

References

Discussion

Maternal body mass index: the functional significance during reproduction

(introduction...)

Introduction

The East Java Pregnancy Study (EJPS)

Results

Discussion

References

Discussion

Maternal body mass index and pregnancy outcome in the nutrition collaborative research support program

(introduction...)

Introduction

The Nutrition CRSP

Nutritional status and BMI of the women

Relationship between maternal BMI and other anthropometric variables

BMI and maternal weight gain

BMI and post-partum weight and fat retention

Additional analyses from the Mexico CRSP

Maternal BMI and size of the infant at birth

Maternal BMI and infant size during early lactation

Predictors of maternal BMI

Conclusions and implications for assessment

References

Discussion

Body mass index and lactation performance

(introduction...)

Introduction

Methods

Basic physiology of lactation

Is BMI a useful discriminator of lactation performance in terms of breast-milk quantity?

Is BMI a useful discriminator of lactation performance in terms of breast-milk quality?

Conclusions

References

Discussion

Assessing the linkages between low body mass index and morbidity in adults: evidence from four developing countries

(introduction...)

Introduction

BMI trends

Morbidity experience

Correlation between low BMI and morbidity

Conclusions and summary

References

Discussion

Body mass index and illness in rural Sarawak

(introduction...)

Introduction

Methods

Results

Discussion

Conclusions

References

Discussion

An assessment of nutritional factors affecting the BMI of a population

(introduction...)

Introduction

Methods

Results

Discussion

References

Body mass index: its relationship with food consumption and socioeconomic variables in Brazil

(introduction...)

Introduction

Methods

Results

1. BMI of adults and food consumption: some methodological issues

2. BMI and socio-economic level

3. The effect of age and sex on adult BMIs

4. Adult BMI and morbidity

5. Trends of BMI in Brazil

References

Discussion

Use of body mass index in the assessment of adult nutritional status in Vietnam

(introduction...)

Introduction

Results

Effect of low BMI on health status

Conclusions

References

Discussion

Body mass index: a measure of the nutritional status Indian populations

(introduction...)

Introduction

Results

Discussion

References

Discussion

Is body mass index sensitively related to socio-economic status and to economic adjustment? a case study from the Congo

(introduction...)

Introduction

Methods

Results

Discussion

References

The body mass index of Chinese adults in the 1980s*

(introduction...)

Introduction

Methods

Results

Discussion

References

Discussion

Body mass index values in the Cuban adult population

(introduction...)

Introduction

Methods

Results

Discussion

Conclusions

Recommendations

References

Discussion

Body mass index defines the risk of seasonal energy stress in the third world

(introduction...)

Introduction

The big-ecology of seasonality

Impact of seasonality on humans

Biological implications of seasonal weight loss

The world dimensions of biological seasonality

References

Discussion

The choice of cut-off point for distinguishing normal body weights from underweight or 'chronic energy deficiency' in adults

(introduction...)

Introduction

Optimum population BMIs in men

Optimum BMIs in women

Age-related changes in BMI and its implications for the CED classification

Conclusions

References

Use of BMI for monitoring and surveillance, practical issues

(introduction...)

Introduction

'Conventional' nutritional surveillance

Proposed nutritional surveillance

Discussion

Appendix 1.

Appendix 2.

Analysing cross-sectional anthropometric data

(introduction...)

Introduction

Analysis of anthropometric variables

Use of statistics for predictive purposes

Brief conclusions and recommendations

References

Discussion

Methods

Subjects

The parents of the subjects selected for the sample of the second growth and development study (Berdasco et al., 1991) were the subjects of this survey. After cleaning the data, the total number of adults was 31 662, of whom 11912 were males and 19 750 were females. This difference in the numbers was probably due to the better attendance of mothers for their appointments.

Field work

The adults attended the measuring centres where they were weighed, and had their height, upper arm circumference, triceps and subscapular fat-folds measured. The survey was undertaken by eight measuring teams (two anthropometrists each) working simultaneously from May to December 1982. Individuals living in the country's 14 provinces were measured.

In order to assure the best possible quality in the primary data, anthropometrists were trained in the same measuring procedures utilized in the first national growth and development study (Jordan, 1979), namely, those recommended by UN International Biological Programme (Weiner & Laurie, 1969). The quality of the measurements was also guaranteed through technical supervision by the investigators, and two quality control sessions. In this way, a correct application of measuring techniques was assured and consequently, consistent and uniform measurements were obtained. The adults were measured without shoes and with the lightest clothing possible (underwear and trousers or skirt) from which their nude weight could be estimated as 1 kg less than the recorded weight.

Criteria to define urban or rural dwelling

The basic definitions of the 1981 Cuban Population and Housing Census were used (Comitstatal de Estadisticas, 1984).

Urban dwellings were categorized as:

(a) all places with a population of 2000 or more inhabitants;
(b) all places with a population of 500 to 2000 inhabitants with electricity and three or more facilities such as an aqueduct, paved streets, a sewerage system, medical services and an educational centre; or
(c) all places with a population of 200 to 500 inhabitants with electricity and all of the five facilities listed in (b).

All places with a population of less than 200 inhabitants were considered rural. This category also included places with a population between 200 and 2000 inhabitants and without the facilities available in urban places.

Classification criteria related to educational level

Adults were classified into the following four groups based on the last grade passed:

Group 1: 12th or over (high school graduates, university graduates or students)
Group 2: 9th to 11th (junior high school graduates)
Group 3: 6th to 8th (junior high school not completed; elementary school graduates)
Group 4: 6th grades (elementary school not completed).

Classification criteria related to the type of occupation

Occupation was recorded by questioning the subjects at an interview. They were then classified as follows:

Group 1: Production and service workers (moderate to intense physical activity)
Group 2: Professional, technical and administrative workers (light physical activity)
Group 3: Agricultural workers and small farm workers (mainly intense physical activity)
Group 4: Housewives and students.

Data processing

After cleaning the data, the following indices were calculated: weight/height, Rohrer, Sheldon, Ponderal, Benn (data not shown except for BMI). Correlations were established (Pearson's linear correlation coefficients) with weight, height, triceps fat-fold, subscapular fat-fold and the sum of both fat-folds.

Percentiles 3, 10, 25, 50, 75, 90, 97 of BMI were estimated for each year of age, by sex and by sex and place of dwelling i.e. urban and rural. Calculations were also made by 10 year groups categorized by sex and by sex and place of dwelling. Classification of the BMI was also carried out with the cut-off points proposed by James, Ferro-Luzzi & Waterlow (1988) for CED:

CED 3 BMI <16.0
CED 2 BMI 16.0-16.9
CED 1 BMI 17.0-18.4.

To this classification were added the following categories:

Underweight BMI 18.5-19.9
Normal BMI 20.0-24.9
Obese 1 BMI 25.0-29.9
Obese 2 BMI 30.0-39.9
Obese 3 BMI 240.0.

These groupings were used to classify BMI by 10 year intervals and by sex, sex and place of dwelling, sex and educational level, sex and occupation, sex and height (where the shortest < percentile 3, and the tallest were > percentile 97). Another classification was also made by percentiles of BMI and height by sex. Finally, the cut-off points of 'normal' BMI for the Cuban population were estimated by the percentage distribution of individuals by category of fat-folds in relation to the BMI groups and by sex and two age groups, 20-39 and 40-59 years. More detailed information of the data processing may be found elsewhere (Berdasco & Romero, 1992).