Dietary patterns associated with fat and bone mass in young children

Abstract

Background: Obesity and osteoporosis have origins in childhood, and both are affected by dietary intake and physical activity. However, there is little information on what constitutes a diet that simultaneously promotes low fat mass and high bone mass accrual early in life.

Objective: Our objective was to identify dietary patterns related to fat and bone mass in children during the age period of 3.8-7.8 y.

Design: A total of 325 children contributed data from 13 visits over 4 separate study years (age ranges: 3.8-4.8, >4.8-5.8, >5.8-6.8, and >6.8-7.8 y). We performed reduced-rank regression to identify dietary patterns related to fat mass and bone mass measured by dual-energy X-ray absorptiometry for each study year. Covariables included race, sex, height, weight, energy intake, calcium intake, physical activity measured by accelerometry, and time spent viewing television and playing outdoors.

Results: A dietary pattern characterized by a high intake of dark-green and deep-yellow vegetables was related to low fat mass and high bone mass; high processed-meat intake was related to high bone mass; and high fried-food intake was related to high fat mass. Dietary pattern scores remained related to fat mass and bone mass after all covariables were controlled for (P < 0.001-0.03).

Conclusion: Beginning at preschool age, diets rich in dark-green and deep-yellow vegetables and low in fried foods may lead to healthy fat and bone mass accrual in young children.

FIGURE 1

Fat mass of children with low (quartile 1), medium (quartiles 2 and 3), and high (quartile 4) scores for dietary pattern 1 (A, C, E, and G) and dietary pattern 2 (B, D, F, and H) at progressively higher ages. P values are for the effect of the continuous variables for dietary pattern score in the full model adjusted for the other dietary pattern score, height, exact age, race, sex, accelerometer counts per minute, television-viewing time, outdoor playtime, calcium intake, and energy intake; R² is for the full model. Plotted values are least-squares means from the full model with dietary pattern scores treated as categorical variables. The sample included 18–19% black and 51–52% male subjects at each of the 4 study years. In year 4, relevant coefficients for dietary pattern 2 are reversed compared with years 1–3 (Table 3): coefficients are negative for deep-yellow vegetables and processed meats and positive for fried chicken and fish and fried potatoes. This means that a child with high intakes of deep-yellow vegetables and processed meats and a low intake of fried foods has a low dietary pattern 2 score in year 4; thus, a low dietary pattern 2 score in year 4 is linked to lower fat mass. Therefore, the finding for year 4 is similar to the findings for years 1–3.

FIGURE 2

Bone mass of children with low (quartile 1), medium (quartiles 2 and 3), and high (quartile 4) scores for dietary pattern 1 (A, C, E, and G) and dietary pattern 2 (B, D, F, and H) at progressively higher ages. P values are for the effects of the continuous variables for dietary pattern score in the full model adjusted for the other dietary pattern score, height, exact age, race, sex, accelerometer counts per minute, television-viewing time, outdoor playtime, calcium intake, and energy intake; R² is for the full model. Plotted values are least-squares means from the full model with dietary pattern scores treated as categorical variables. The sample included 18–19% black and 51–52% male subjects at each of the 4 study years. In year 4, relevant coefficients for dietary pattern 2 are reversed compared with years 1–3 (Table 3): coefficients are negative for deep-yellow vegetables and processed meats and positive for fried chicken and fish and fried potatoes. This means that a child with high intakes of deep-yellow vegetables and processed meats and a low intake of fried foods has a low dietary pattern 2 score in year 4; thus, a low dietary pattern 2 score in year 4 is linked to higher bone mass. Therefore, the finding for year 4 is similar to the findings for years 1–3.