Megan Witbracht

Dairy Foods in a Moderate Energy Restricted Diet Do Not Enhance Central Fat, Weight, and Intra-Abdominal Adipose Tissue Losses nor Reduce Adipocyte Size or Inflammatory Markers in Overweight and Obese Adults: A Controlled Feeding Study.

Background. Research on dairy foods to enhance weight and fat loss when incorporated into a modest weight loss diet has had mixed results. Objective. A 15-week controlled feeding study to determine if dairy foods enhance central fat and weight loss when incorporated in a modest energy restricted diet of overweight and obese adults. Design. A 3-week run-in to establish energy needs; a 12-week 500 kcal/d energy reduction with 71 low-dairy-consuming overweight and obese adults randomly assigned to diets: ≤1 serving dairy/d (low dairy, LD) or ≤4 servings dairy/d (adequate dairy, AD). All foods were weighed and provided by the metabolic kitchen. Weight, fat, intra-abdominal adipose tissue (IAAT), subcutaneous adipose tissue (SAT) macrophage number, SAT inflammatory gene expression, and circulating cytokines were measured. Results. No diet differences were observed in weight, fat, or IAAT loss; nor SAT mRNA expression of inflammation, circulating cytokines, fasting lipids, glucose, or insulin. There was a significant increase (P = 0.02) in serum 25-hydroxyvitamin D in the AD group. Conclusion. Whether increased dairy intake during weight loss results in greater weight and fat loss for individuals with metabolic syndrome deserves investigation. Assessment of appetite, hunger, and satiety with followup on weight regain should be considered.

Associations among endocrine, inflammatory, and bone markers, body composition and weight loss induced bone loss

INTRODUCTION Weight loss reduces co-morbidities of obesity, but decreases bone mass. PURPOSE Our aims were to (1) determine if adequate dairy intake attenuates weight loss-induced bone loss; (2) evaluate the associations of endocrine, inflammatory and bone markers, anthropometric and other parameters to bone mineral density and content (BMD, BMC) pre- and post-weight loss; and (3) model the contribution of these variables to post weight-loss BMD and BMC. METHODS Overweight/obese women (BMI: 28-37 kg/m2) were enrolled in an energy reduced (-500 kcal/d; -2092 kJ/d) diet with adequate dairy (AD: 3-4 servings/d; n=25, 32.2±8.8 years) or low dairy (LD: ≤1 serving/d; n=26, 31.7±8.4 years). BMD, BMC and body composition were measured by DXA. Bone markers (CTX, PYD, BAP, OC), endocrine (PTH, vitamin D, leptin, adiponectin, ghrelin, amylin, insulin, GLP-1, PAI-1, HOMA) and inflammatory markers (CRP, IL1-β, IL-6, IL-8, TNF-α, cortisol) were measured in serum or plasma. PA was assessed by accelerometry. RESULTS Following weight loss, AD intake resulted in significantly greater (p=0.004) lumbar spine BMD and serum osteocalcin (p=0.004) concentration compared to LD. Pre- and post-body fat was negatively associated with hip and lumbar spine BMC (r=-0.28, p=0.04 to -0.45, p=0.001). Of note were the significant negative associations among bone markers and IL-1β, TNFα and CRP ranging from r = -0.29 (p=0.04) to r = -0.34 (p=0.01); magnitude of associations did not change with weight loss. Adiponectin was negatively related to change in osteocalcin. Factor analysis resulted in 8 pre- and post-weight loss factors. Pre-weight loss factors accounted for 13.7% of the total variance in pre-weight loss hip BMD; post-weight loss factors explained 19.6% of the total variance in post-weight loss hip BMD. None of the factors contributed to the variance in lumbar spine BMD. CONCLUSION AD during weight loss resulted in higher lumbar spine BMD and osteocalcin compared to LD. Significant negative associations were observed between bone and inflammatory markers suggesting that inflammation suppresses bone metabolism. Using factor analysis, 19.6% of total variance in post-weight loss hip BMD could be explained by endocrine, immune, and anthropometric variables, but not lumbar spine BMD.

Performance on the Iowa Gambling Task is related to magnitude of weight loss and salivary cortisol in a diet-induced weight loss intervention in overweight women.

The overall objective of this study was to examine the relationship between executive function, specifically decision-making, and weight loss. We used the Iowa Gambling Task (IGT) to characterize decision-making and compared performance on this task to weight loss in obese women (n=29) participating in a 12-week controlled, calorie-reduced intervention. We hypothesized that a greater amount of weight loss over the course of the intervention would be associated with better performance on the IGT, assessed at the end of the intervention. The intervention led to significant weight loss of 5.8±3.1 kg (p<0.05) and fat loss of 5.1±3.0 kg (p<0.05). Body weight and fat mass losses over the 12-week intervention varied widely, ranging from -12.5 kg to 0.0 kg for body weight and -10.4 kg to +0.8 kg for fat mass. A greater amount of body weight loss was correlated (r=0.425; p<0.01) with a higher total score on the IGT. Similarly, the reduction in body fat mass was also correlated with the IGT score (r=0.408; p<0.05). We examined other physiological (salivary cortisol), metabolic (resting energy expenditure), and behavioral (food intake; dietary restraint) factors that might be related to differences in the magnitude of weight loss. Of these variables, ad libitum consumption of energy, fat and protein during a buffet meal was inversely related to weight loss (r=-0.428; p<0.05; r=-0.375; p<0.05 and r=-0.472; p=0.01, respectively). The present study is the first to report an association between diet-induced weight loss and performance on the IGT, and this association was specific to the loss of body fat. Our results suggest that differences in weight loss may be linked to executive function that involves decision-making about events that have emotionally or socially salient ramifications. These findings underscore the need to further investigate higher cognitive and neuroendocrine pathways that may influence or be altered by the process of dieting and weight loss.

Dairy Food Consumption and Meal-Induced Cortisol Response Interacted to Influence Weight Loss in Overweight Women Undergoing a 12-Week, Meal-Controlled, Weight Loss Intervention

Dairy food enhances weight loss in animal models, possibly by modifying the metabolic effects of cortisol. This study determined in overweight women (ages 20.0-45.9 y; n = 51) whether including dairy food in an energy-restricted diet affects cortisol concentrations and whether differences in provoked cortisol explain the magnitude of weight loss. Women received either an adequate amount of dairy food (AD), the equivalent of ≥711 mL/d milk, or a low amount of dairy food (LD), the equivalent to ≤238 mL/d milk, in a 12-wk, energy-restricted dietary intervention. Participants were tested in a 12-h laboratory visit, which included 2 standard meals and a dinner buffet that was consumed ad libitum. Salivary cortisol was measured from waking to bedtime. Energy restriction increased (P ≤ 0.04) the minimum and decreased (P ≤ 0.02) the diurnal amplitude in the salivary cortisol concentration from baseline to postintervention. Energy restriction enhanced the dinner meal-stimulated salivary cortisol response (DMR) (P ≤ 0.02) but only in the LD group. Compared with the LD treatment, the AD treatment induced (P ≤ 0.04) greater reductions in body weight and fat, but only in women characterized as having a baseline DMR (responders) (n = 26); weight and fat lost in the AD and LD groups were similar in nonresponders (n = 25). Overall, energy restriction dampened diurnal salivary cortisol fluctuations [symptomatic of hypothalamic-pituitary-adrenal (HPA) axis dysfunction] and enhanced dinner meal-stimulated salivary cortisol concentrations. The AD treatment prevented the latter. Furthermore, certain phenotypic markers of HPA axis function may help to expose the weight-reducing effects of consuming dairy food.

A Potential Tool for Clinicians; Evaluating a Computer-Led Dietary Assessment Method in Overweight and Obese Women during Weight Loss

Many Americans are attempting to lose weight with the help of healthcare professionals. Clinicians can improve weight loss results by using technology. Accurate dietary assessment is crucial to effective weight loss. The aim of this study was to validate a computer-led dietary assessment method in overweight/obese women. Known dietary intake was compared to Automated Self-Administered 24-h recall (ASA24) reported intake in women (n = 45), 19–50 years, with body mass index of 27–39.9 kg/m2. Participants received nutrition education and reduced body weight by 4%–10%. Participants completed one unannounced dietary recall and their responses were compared to actual intake. Accuracy of the recall and characteristics of respondent error were measured using linear and logistic regression. Energy was underreported by 5% with no difference for most nutrients except carbohydrates, vitamin B12, vitamin C, selenium, calcium and vitamin D (p = 0.002, p < 0.0001, p = 0.022, p = 0.010, p = 0.008 and p = 0.001 respectively). Overall, ASA24 is a valid dietary assessment tool in overweight/obese women participating in a weight loss program. The automated features eliminate the need for clinicians to be trained, to administer, or to analyze dietary intake. Computer-led dietary assessment tools should be considered as part of clinician-supervised weight loss programs.