Editorial: The adipose-cell hypothesis

Lipocyte hyperplasia and sexual maturation of Japanese quail (Coturnix coturnix japonica)

1. Hyperplastic growth of adipose tissue in Japanese quail (Coturnix coturnix japonica) was examined in relation to sexual maturity to determine whether fat cell number is fixed in mature individuals of this species. 2. Total DNA concentrations in the lipid (lipocyte) and non-lipid (stroma) fractions of collagenase (EC 3.4.24.3)-digested abdominal (retroperitoneal) fat depots were determined on a chronological-age basis from 28 to 240 d of age. The in vivo incorporation of [methyl-3H]thymidine into DNA of both the lipocyte and stroma fractions of abdominal fat from both ad lib. and restricted-fed (75% of ad lib.) females was also examined at ages before and subsequent to sexual maturity. 3. In both males and females, significant increases in abdominal fat weights at ages beyond sexual maturity were associated with increased lipocyte DNA. Regardless of the feeding regimen and stage of maturity, substantial radioactivity was recovered from both the stromal and lipocyte fractions of abdominal fat when female quail were examined 24 h after the administration of tritiated thymidine. When examined 5 d post-injection, the majority of the radioactivity was contained in the lipid fraction of collagenase-digested adipose tissue. 4. Both the total DNA content of adipose tissue and the incorporation of tritiated thymidine into adipose tissue indicated that lipocyte hyperplasia contributes to postmaturational increases in fat deposition.

Correlates of obesity

Designed to create composites of eating behavior questionnaire items and determine their relationship to an obesity index within three subsamples of participants in three Navy-sponsored weight-reduction programs (N = 1,878). After item and scale analyses were performed on questionnaire items that pertained to eating behaviors, history of weight problems, activities, and feelings about food and dieting, scores for the resultant composites were computed for individuals within the three subsamples. Results of multiple-regression analyses indicated that the strongest correlates of obesity within each subsample were the Overweight History, Food Obsession, and Activities composites; the multiple R was .49 for Marine recruits, .46 for the other male subsample, and .32 for women. The Emotional Eater composite was included in the multiple regression for the women's subsample. Personality characteristics also were found to be associated with the obesity index in the men's and women's subsamples. Future studies will examine the value of these variables as predictors of weight loss and maintenance of weight loss.

Excessive carbohydrate intake in pregnancy and neonatal obesity: study in Cap Bon, Tunisia

A high incidence (over 20%) of obesity was found in 250 neonates living in a rural area of Tunisia, by using weight and ponderal index per gestational age as the nutritional index. Maternal diabetes was probably excluded. Two surveys on nutritional habits--one on the general population and the other on pregnant women--showed a tendency to consume a high carbohydrate and low protein diet. The effect of a badly balanced maternal diet on the fetus is discussed.