Monitoring Dietary Change in a Low-Fat Diet Intervention Study: Advantages of Using 24-Hour Dietary Recalls vs Food Records

Objective The purpose of the study was to evaluate two methods of dietary assessment for monitoring change in fat intake in a low-fat diet intervention study.Design The two dietary assessment methods were a 4-day food record (4DFR) and an unannounced 24-hour dietary recall conducted by telephone interview (referred to as a telephone recall [TR]). Subjects were assigned randomly to either a low-fat diet intervention group or a control group that received no counseling about fat intake. Dietary data were collected at baseline, 6 months, and 12 months.Subjects Two hundred ninety postmenopausal women with localized breast cancer were recruited at seven clinical centers in the United States.Statistical analysis Analysis of variance was used to test for significant differences in mean fat and energy intakes.Results Three sources of error were identified: (a) an instrument effect, suggesting underreporting at baseline of approximately 8% in mean energy intake and 11% in mean fat intake in the TR group compared with the 4DFR group (P=.0001); (b) a repeated measures effect observed for the 4DFR, suggesting underreporting of approximately 7% for energy intake and 14% for fat intake in the control group at 6 and 12 months compared with baseline values (P<.001); and (c) an adherence effect (or compliance bias), suggesting greater compliance to the low-fat intervention diet when subjects were keeping food records than when estimates were based on the unannounced TR. Compared with the TR, the 4DFR overestimated the extent of fat reduction in the low-fat diet intervention group by 41% (P=.08) and 25% (P=.62) at 6 and 12 months, respectively.Application Multiple days of unannounced 24-hour recalls may be preferable to multiple-day food records for monitoring dietary change in diet intervention studies. J Am Diet Assoc. 1996; 96:574-579.     

Controlled Portions of Presweetened Cereals Present no Glycemic Penalty in Persons with Insulin-Dependent Diabetes Mellitus

Objective to determine metabolic responses to commercially sweetened flaked corn cereal, unsweetened flaked corn cereal, glucose, and sucrose in teenagers and young adults with insulin-dependent diabetes mellitus (IDDM).Design A crossover design in which each subject consumed test meals in random order on 4 separate days at least 72 hours apart.Setting The inpatient setting of the General Clinical Research Center of the Indiana University Medical Center Hospital.Subjects Sixteen males and eight females, aged 14 to 25 years, with IDDM.Interventions After fasting overnight, each subject underwent challenge tests with 50 g carbohydrate per 1.73 m² of body surface area from sweetened flaked corn cereal, unsweetened flaked corn cereal, sucrose, and glucose. All subjects were maintained on continuous intravenous infusion of insulin overnight (euglycemic goal=3.9 to 6.7 mmol/L), with a constant basal insulin dose infused before and throughout a 3-hour postprandial period.Main outcome measures Plasma glucose, free insulin, triglycerides, and free fatty acid levels measured at baseline and 15, 30, 45, 60, 90, 120, 150, and 180 minutes after meals.Statistical analyses performed Comparisons among the four meals were made using two-way repeated measures analyses of variance followed by the Newman-Keuls multiple comparison procedure to identify specific differences among meals. The areas under the response curves were compared using one-way repeated measures analysis of covariance, adjusted for baseline values.Results The response to glucose for the area under the 3-hour blood glucose response curve was significantly greater than the response to sucrose (P=.006 by repeated measures analysis of variance); the areas for the two cereals (not significantly different from one another) were between the glucose and sucrose areas. At 3 hours, glycemia differed significantly among three of the meals: unsweetened flaked corn cereal>sweetened flaked corn cereal>sucrose (P<.001). Glucose at 3 hours was greater than sucrose (P<.001). There were no significant differences for free insulin, triglycerides, or free fatty acids.Applications Equivalent gram amounts of carbohydrate as presweetened breakfast cereals are not detrimental to persons with IDDM compared with unsweetened cereals. Therefore, presweetened cereals can be used in the correct portion sizes and based on the number of carbohydrate or starch servings in a person's diabetic meal plan. J Am Diet Assoc. 1996; 96:458-463.     

Implementing A Ketogenic Diet Based on Medium-chain Triglyceride Oil in Pediatric Patients with Cancer

Traditionally, a ketogenic diet is given to drug-resistant children with epilepsy to improve seizure control. Inducing a ketogenic state in patients with cancer may be a useful adjunct to cancer treatment by affecting tumor glucose metabolism and growth while maintaining the patient's nutritional status. A ketogenic diet consisting of 60% medium-chain triglyceride (MCT) oil, 20% protein, 10% carbohydrate, and 10% other dietary fats was provided to a select group of pediatric patients with advanced-stage cancer to test the effects of dietary-induced ketosis on tumor glucose metabolism. Issues of tolerance and compliance for patients consuming an oral diet (consisting of normal table foods and daily MCT oil “shakes”) and for patients receiving an enteral formula are reviewed. Preliminary use of the MCT oil-based diet suggests a potential in pediatric patients with cancer. J Am Diet Assoc. 1995; 95:693-697.     

Determinants of Body Size Perceptions and Dieting Behavior in a Multiethnic Group of Hospital Staff Women

Objective This study was designed to identify determinants of body size perceptions and their relationship to dietary behavior in a multiethnic group of women.Design A single interview consisting of the Massara and Stunkard body image cards (1979) and questionnaires on sociocultural background, anthropometry, and dieting history were administered to volunteers from the staff of a hospital.Subjects The sample was a convenience sample of 186 women representing a range of staff positions recruited from Methodist Hospital in Brooklyn, NY; 174 completed the study. Data on 150 women are presented in this article.Results Height and weight-for-height were stronger predictors of accuracy of perceived body size than ethnicity. Tall, slight women were more likely to overestimate and short, heavy women were more likely to underestimate actual body size. Ethnicity had an interactive effect with height as taller European Americans were more likely to perceive their body size as larger than actual compared with Afro-Caribbeans and African Americans. Women with a history of dieting were more likely to overestimate their size and to view it as different from what is perceived as attractive to others.Applications/conclusions Based on the results, we conclude that body size is a stronger predictor of accuracy of perceived body size than ethnicity; and dieters overestimate their body size and believe it to be heavier than their social group would prefer. J Am Diet Assoc. 1996; 96:252-256.