Rajni Singh

Publications (2)13.34 Total impact

• Article: Calcium, dairy products, and energy balance in overweight adolescents: a controlled trial.

  Connie M Weaver, Wayne W Campbell, Dorothy Teegarden, Bruce A Craig, Berdine R Martin, Rajni Singh, Michelle M Braun, John W Apolzan, Tamara S Hannon, Dale A Schoeller, Linda A DiMeglio, Yvonne Hickey, Munro Peacock
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  ABSTRACT: Dairy product and calcium consumption have been associated with modifying body fat and body weight in children and adults. In overweight adolescent boys and girls, we aimed to determine the effect of the doubling of habitual calcium intake to the recommended intake from dairy or calcium carbonate on energy balance and purported mechanisms including fecal fat excretion, macronutrient use, and parathyroid hormone suppression. Twenty-five girls with a mean (±SD) BMI (in kg/m(2)) of 33 ± 5 and 17 boys with a BMI of 28 ± 5, aged 12-15 y, participated in two 3-wk controlled feeding sessions that used a crossover design in random order as a summer research camp. In one session, 756 mg Ca/d was consumed; in the other session, an additional 650 mg Ca/d was provided as dairy or calcium carbonate supplements that were matched to the control in macronutrient content. Total energy and macronutrient intakes were controlled and were the same for the 2 sessions for each subject. Primary outcome measures were energy balance, fecal fat excretion, lipid oxidation, and postprandial energy expenditure. There were no effects of quantity or source of calcium on energy or fat balance, despite calcium-induced increases (P <0.01) in postprandial serum parathyroid hormone suppression. These data lend little evidence to support the proposed mechanisms for the relation between an increase in calcium intake from calcium carbonate or dairy and weight loss or weight maintenance in children. This trial was registered at clinicaltrials.gov as NCT00592137.
  American Journal of Clinical Nutrition 09/2011; 94(5):1163-70. · 6.67 Impact Factor
• Article: Comparison of self-reported, measured, metabolizable energy intake with total energy expenditure in overweight teens.

  Rajni Singh, Berdine R Martin, Yvonne Hickey, Dorothy Teegarden, Wayne W Campbell, Bruce A Craig, Dale A Schoeller, Deborah Anne Kerr, Connie M Weaver
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  ABSTRACT: The accuracy of dietary energy assessment tools is critical to understanding the role of diet in the increasing rate of obesity. The purposes of our study in overweight adolescent boys and girls were 1) to assess the energy reporting bias of diet records against the referent of total energy expenditure (TEE) and 2) to compare the methods of determining energy needs by using measured metabolizable energy intake (MEI) and TEE. Twenty girls [12-15 y, body mass index (in kg/m2) = 33.0 +/- 5] and 14 boys (12-14 y, body mass index = 27.4 +/- 4) participated in 2- to 3-wk metabolic balance studies. TEE was measured by using doubly labeled water (TEE(DLW)), and MEI was measured by bomb calorimetry of composite daily diet, urine, and fecal collections. Food records were collected before each study. Food records underreported TEE(DLW) by 35 +/- 20%. Underreporting of energy intake was correlated with all macronutrient intake concentrations (g or kcal) (P < 0.0001). A multiple regression model showed that 86.4% of the variance in underreporting error was explained by dietary fat (g), BMI, and sex. The intrasubject CV was 3.9% for TEE(DLW) and 9.9% for MEI. MEI for weight stability (MEI(wtstb)) averaged 99 +/- 11% of TEE. The increased underreporting of dietary intake with increasing body weight in teens may explain in part previous reports noting that there has been an increased incidence of obesity, although energy intakes have not appeared to increase. MEI(wtstb) and TEE(DLW) gave similar estimates of energy needs. This trial was registered at clinicaltrials.gov as NCT 00592137.
  American Journal of Clinical Nutrition 05/2009; 89(6):1744-50. · 6.67 Impact Factor