Sibylle Kranz

University of Virginia | UVa · Department of Kinesiology and Adjunct FacultyPublic Health Sciences

In humans, dietary patterns impact weight and metabolism differentially across individuals. To uncover genetic determinants for differential dietary effects, we subjected four genetically diverse mouse strains to humanized diets (American, Mediterranean, vegetarian, and vegan) with similar macronutrient composition, and performed body weight, metab...

Context: Ghrelin circulates in acylated (AG) and deacylated (DAG) forms, which are known to affect appetite. Although acute exercise has been shown to modulate ghrelin levels, data on the impact of exercise intensity on AG and DAG levels and their effects on appetite are sparse and primarily limited to males. Objective: To investigate the effect of...

Ghrelin is a peptide hormone that affects hunger, energy intake, and growth hormone secretion. Ghrelin circulates in two isoforms: acyl ghrelin (AG) and deacylated ghrelin (DAG). Acute exercise is associated with ghrelin suppression, yet most data is in young, trained males and only AG is measured. PURPOSE: To investigate the effects of exercise in...

Background: Ghrelin is an orexigenic hormone primarily released by the stomach and has two isoforms: acylated (AG) and de-acylated (DAG), that appear to have different functions in humans. Objective: To perform a systematic review and meta-analysis of the association between plasma levels of total ghrelin (TG), AG, and DAG and perceptions of hun...

Background: Fruit and vegetable (FV) consumption in children in the United States (US) is very low. Adequate FV consumption is required for proper development during childhood, and dietary habits are established during preschool-age and tend to persist into adulthood. As most U.S. preschool-aged children attend childcare or preschool, this may be...

Many young adults on the autism spectrum do not attain the recommended minimum weekly amount of moderate to vigorous physical activity (MVPA) to prevent significant health risks. Autism symptoms as well as environmental factors may play a key role in the physical activity (PA) behaviors of young adults on the autism spectrum. The socioecological mo...

Objective To characterize patterns of fruit and vegetable (F&V) intake in US adults with and without chronic kidney disease (CKD). Methods We used 24-hr dietary recall data from multiple cycles of the National Health and Nutrition Examination Survey (NHANES) spanning 3 groups from 1988-2018 (1988-1994; 2003-2010; 2011-2018). We categorized F&Vs ba...

Objectives Research suggests the active ingredient in vinegar, acetic acid, may reduce appetite, thereby reducing energy consumption. This systematic review aimed to assess the effect of vinegar or acetic acid on appetite and subsequent food intake in humans in the published literature. Methods All human subject studies, regardless of age or healt...

Objectives To examine the effect of ad-libitum low-glycemic index (GI; high fiber) versus high-GI diet on energy intake, diet quality (Healthy Eating Index 2015 (HEI-2015)), self-reported feelings of hunger and fullness, liking of the foods, and physical activity (PA) in preschoolers. Methods Twenty-five healthy preschoolers (aged 48 ± 7.3 mo, 47%...

Research suggests that the active ingredient in vinegar, acetic acid, may reduce appetite, thereby reducing energy consumption. This article aims to assess the effect of vinegar or acetic acid on appetite measures and subsequent food intake in humans. This was conducted as a systematic literature review adhering to the Preferred Reporting Items for...

The purpose of this study was to investigate Healthy Eating Index 2015 (HEI-2015) and Energy-Adjusted Dietary Inflammatory Index (E-DIITM) scores in women’s cancer survivors and to examine socio-economic (SES) characteristics associated with these two diet indices. In this cross-sectional study, survivors of women’s cancers completed a demographic...

Autism Spectrum Disorder (ASD) affects two percent of American children and often results in neophobia, hypersensitivity to foods, and firmly set food preferences, leading to higher proportions of individuals suffering from diet-related chronic diseases. Our objective was to conduct an explorative pilot study to examine parents’ perception of food...

We evaluated the effect of preoperative standard medical care (SC) vs. unsupervised aerobic exercise combined with SC (EX + SC) on cardiometabolic health and quality of life (QoL) 30 days after bariatric surgery. Bariatric patients (n = 14, age: 42.3 ± 2.5 years, body mass index: 45.1 ± 2.5 kg/m2 ) were match-paired to presurgical SC (n = 7) or EX...

Objective This crossover study explored the impact of a single bout of exercise on insulin-stimulated responses in conduit arteries and capillaries. Methods Twelve sedentary adults (49.5 [7.8] years; maximal oxygen consumption [VO2max]: 23.7 [5.4] mL/kg/min) with obesity (BMI 34.5 [4.3] kg/m²) completed a control and exercise bout (70% VO2max to e...

Objectives In 2018, women's cancers accounted for 38.6% of new cases and 26.9% of cancer deaths in females worldwide. The risk of recurrence is partially attributed to lifestyle factors linked to inflammation, including diet quality. Adherence to U.S Department of Agriculture Dietary Guidelines, measured with the Healthy Eating Index (HEI-2015), an...

Objectives Internal and external factors, including glycemic index (GI), regulate food intake in adults, but little is known about the effect of GI on appetite in children. We examined how low- GI (high fiber) diet changed energy intake, diet quality (Healthy Eating Index 2015 (HEI-2015)), self-reported feelings of hunger, and salivary ghrelin in p...

Background: Due to concerns about hyperkalemia, the recommendation for patients with chronic kidney disease (CKD) is to limit intakes of foods high in potassium, including certain types of nuts, fruits and vegetables (F&V). Detailed patterns of F&V intake have not been described in patients with CKD, limiting our ability to study higher or lower ri...

The executive functioning skill set, which includes working memory, cognitive flexibility, and inhibitory control, begins developing in early life and continues into adulthood. Preschoolers’ abilities to perform those skills may be influenced by diet. The purpose of this study was to explore the acute effects of consuming a low-GI diet compared to...

Context: Sport-related concussion (SRC) is characterized by a pathological neurometabolic cascade that results in an increased intracranial energy demand with decreased energy supply. Little is known about the whole-body energy-related effects of SRC. Objective: To examine factors associated with whole-body resting metabolic rate (RMR), total en...

Objective Examine if adding aerobic exercise to standard medical care (EX+SC) prior to bariatric surgery improves metabolic health in relation to surgical outcomes. Methods Fourteen bariatric patients (age: 42.3±2.5y, BMI: 45.1±2.5 kg/m²) met inclusion criteria and were match-paired to pre-operative SC (n = 7) or EX+SC (n = 7; walking 30min/d, 5d/...

Objective Examine the effect of aerobic exercise (EX) combined with standard medical care (SC) (EX + SC) compared to SC alone on cardiometabolic health and quality of life in relation to surgical outcomes. Methods Patients receiving bariatric surgery were match-paired to 30 days of pre-operative SC (n = 7, 1 male, 39.0 ± 5.3 years, body mass index...

Objective: To measure alterations in mood, psychological, and behavioral factors in collegiate athletes throughout recovery from sport concussion (SC) compared with matched controls. Setting: University research laboratory. Participants: Twenty (55% female) division I collegiate athletes with SC (19.3 ± 1.08 years old, 1.77 ± 0.11 m, 79.6 ± 23...

Background Sport concussion (SC) causes an energy crisis in the brain by increasing energy demand, decreasing energy supply, and altering metabolic resources. Whole-body resting metabolic rate (RMR) is elevated after more severe brain injuries, but RMR changes are unknown after SC. The purpose of this study was to longitudinally examine energy-rela...

In today’s research environment, children’s diet, physical activity, and other lifestyle factors are commonly studied in the context of health, independent of their effect on cognition and learning. Moreover, there is little overlap between the two literatures, although it is reasonable to expect that the lifestyle factors explored in the health-fo...

No short-term exercise data exist testing whether training intensity modifies hormonal and perceived appetite in obese adults with prediabetes. Therefore, we compared the effects of short-term moderate-continuous (CONT) vs. high-intensity interval (INT) training on appetite regulation. Twenty-eight obese adults [age: 61.3 ± 1.5 yr; body mass index...

Background: Although the purpose of federal dietary guidance is to improve eating habits, few studies have described awareness of guidance and concurrent diet quality. Objective: The objective of the current study was to examine the prevalence of individuals who reported hearing of dietary guidance icons and to describe the association between h...

Bariatric surgery is an effective and durable treatment for individuals with obesity and its associated comorbidities. However, not all patients meet weight loss and/or cardiometabolic goals following bariatric surgery, suggesting that some people are bariatric surgery resistant. The reason for this resistance is unclear, but potential factors, suc...

The United Kingdom (UK) is an island and its culture, including diet, is heavily influenced by the maritime resources. Dietary guidance in the UK recommends intake of fish, which provides important nutrients, such as long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA). This study was designed to describe the fish intake habits of UK children...

The United Kingdom (UK) is an island and its culture, including diet, is heavily influenced by the maritime resources. Dietary guidance in the UK recommends intake of fish, which provides important nutrients, such as long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA). This study was designed to describe the fish intake habits of UK children...

Dietary fiber (DF), found in whole fruits, vegetables, and whole grains (WG), is considered a nutrient of concern in the US diet and increased consumption is recommended. The present study was designed to highlight this critical importance of the difference between WG, high-fiber WG, and sources of fiber that are not from WG. The study is based on...

Background: In the United States, 17% of children are currently obese. Increasing feelings of fullness may prevent excessive energy intake, lead to better diet quality, and promote long-term maintenance of healthy weight. Objective: The purpose of this study was to develop a fullness-rating tool (aim 1) and to determine whether a high-protein (H...

Background: A composite measure of diet quality is preferable to an index of nutrients, food groups, or health-promoting behaviors in dietary assessment. However, to date, such a tool for Chinese children is lacking. Objective: Based on the current Chinese Dietary Guidelines and Dietary Reference Intakes, a dietary index for Chinese school-aged...

Background: The nutrients provided by fruits and vegetables are essential for optimal growth and development, yet fruits and vegetables continue to be under-consumed by most children. Children’s liking of foods is a primary predictor of intake, suggesting that increasing children’s liking of fruits and vegetables may serve as an initial step toward...

Objective: Dietary eicosapentaenoicacid (EPA) and docosahexaenoic acid (DHA) are found in the highest concentrations in fish and seafood. As important nutrients for brain and eye development and function, their consumption levels are of public health interest, especially in children. This study was conducted to examine children’sreported consumptio...

Background: Supermarkets use sales circulars to highlight specific foods, usually at reduced prices. Resulting purchases help form the set of available foods within households from which individuals and families make choices about what to eat. Objective: The purposes of this study were to determine how closely foods featured in weekly supermarke...

Background Current federal dietary guidance recommends regular consumption of seafood (fish + shellfish) for health; however, little is known about how well Americans meet guidelines, particularly population subgroups. Objectives To describe prevalence of seafood consumption and, among consumers, amounts of any seafood, fish, and shellfish eaten b...

Current US federal dietary guidance recommends regular consumption of seafood (fish + shellfish) to promote health; however, little is known about how well Americans meet the guideline, particularly population subgroups that may be at risk for inadequate intake. The purposes of this study were to describe the prevalence of seafood consumption and,...

Background The nutritional content of Americans’ shopping carts is suboptimal despite federal dietary guidance, in this case, the MyPlate consumer icon which displays desired proportions of vegetables, fruits, dairy, grains and protein foods for consumption. Consumers mention print advertising—such as weekly sales circulars—frequently as influencin...

Fruit and vegetable intake is low in most children. Children’s liking of foods predicts intake; therefore, increasing liking of fruits and vegetables (FV) may be an initial step in increasing consumption. The aim of this study was to explore whether offering FV in child‐friendly (CF) shapes increases children’s liking of these foods. A convenience...

Although fish and algae are the only dietary sources of docosahexaenoic acid (DHA), a nutrient critical for brain development, fish is vastly under‐consumed in children. Plant‐based omega‐3 fatty acids can be converted to DHA but the conversion is inefficient. The Dietary Guidelines for Americans recommend consumption of seafood twice a week. We ex...

Fruit and vegetable intake in children falls short of meeting national recommendations. Children’s liking of fruits and vegetables (FV) and availability and accessibility are important determinants of intake. We hypothesized that parents/caregivers would recognize fun‐shaped FV as being child‐friendly (CF) and would be willing to pay slightly more...

Portion size is known to influence food intake in children, but little is known about how visual cues will affect food consumption in this age group. This crossover study tested whether children’s food intake would increase if children had no visual cues (NVC) of food consumption. Two‐to‐five year old children (n=38) were asked to come to Purdue Un...

Diet quality in American children is suboptimal, contributing to risk for overweight, obesity, and development of chronic disease. The aim of this study was to assess the impact of serving high‐fiber snacks twice a day on measures of diet quality in a sample of elementary school children. Participants (n=81) in a community‐based, prospective, rando...

The 2010 Dietary Guidelines for Americans (DGA) recommend that individuals age two years and older reduce intakes of solid fats (SoF) and added sugars (AS; together SoFAS). MyPlate, illustrates the proportions of five major food groups to promote healthy eating (Vegetables, Grains, Protein Foods, Fruits and Dairy). To assess if the foods currently...

Dietary fiber (DF) intake in American children is suboptimal, increasing the risk of GI distress and contributing to poor diet quality. The objective of this study was to determine the effect of introducing two high-fiber snacks per day on gastrointestinal function as well as nutrient and food group intake in healthy children ages 7-11 years old. T...

Background: The Dietary Guidelines for Americans 2010 recommend that Americans age two years and older con-sume seafood, especially fish high in omega-3 polyunsaturated fatty acids, at least twice a week. Although fish is of particular importance during childhood to support proper brain and eye development, it is under-consumed in the US pediatric...

Dietary guidance issued by various global government agencies recommends nut consumption within the context of a healthy-eating pattern. Nuts are nutrient dense and may promote nutrient adequacy. As an energy-dense food, nuts must replace other foods in the diet to prevent an excess of calories. We evaluated how recommending the inclusion of walnut...

To understand key characteristics of mothers who were early adopters of MyPlate (the iconic representation of the 2010 Dietary Guidelines for Americans) in order to speed adoption among others. Through a national online survey, 497 mothers answered questions about MyPlate, demographics, attitudes, and behaviors. Spearman's rho correlation analysis...

The purpose of this repeated exposure, randomized, cross-over quasi-experimental study was to determine the individual and combined impact of a) the timing of serving dessert and b) portion size of main course in 2-5 year old children (n=23) on energy intake at lunch in a childcare setting. Children were served two study lunches (fish or pasta, eac...

Up to 10% of U.S. children suffer from chronic constipation, accounting for 25% of referrals to pediatric gastroenterologists. Constipation can lower health‐related quality of life (HRQOL). Dietary fiber reduces the risk for constipation but is under‐consumed in children. We assessed child‐ and parent‐reported pediatric HRQOL in a sample of 7 to11‐...

The 2010 DGA include a key recommendation to consume at least 50% of grains as whole grains (WG). Dietary fiber (DF) is not included in the food‐based DGA recommendations, but DF consumption is linked to lower obesity risk. WG foods can be high in DF and consumers might consider that WG containing foods are synonymous with high DF foods. We conduct...

Analyzing dietary intake data of nationally representative samples is a highly sought skill, especially in the pursuit of public health recommendations or the evaluation of dietary guidance. Although NHANES are publicly available data and the CDC provides guidance a number of analytical programs to help researchers conduct analysis, the merging of...

To date, few studies have examined correlations between child and parent‐proxy responses in healthy populations. We used the PedsQL™ 4.0 Generic Core Scales to assess child‐ and parent‐reported pediatric HRQOL in a sample of 7 to 11‐year‐old schoolchildren at baseline and at completion of an 8‐week intervention study aimed at increasing dietary fib...

Background Ineffective family interventions for the prevention of childhood obesity have, in part, been attributed to the challenges of reaching and engaging parents. With a particular focus on parent engagement, this study utilized community-based participatory research to develop and pilot test a family-centered intervention for low-income famili...

Obesity has been associated with low diet quality and the suboptimal intake of food groups and nutrients. Two composite diet quality measurement tools are appropriate for Americans 2-18 years old: the Healthy Eating Index (HEI) 2005 and the Revised Children's Diet Quality Index (RC-DQI). The five components included in both indexes are fruits, vege...

Increased fiber intake has been linked with lower risk of overweight and obesity in adults, but data are sparse for children. To address this issue, NHANES 2003-2006 data was used to evaluate (1) the food sources of fiber in children, (2) the dietary fiber density levels and risk of being classified as overweight/obese, and (3) the association betw...