Biomarkers of intestinal permeability are associated with inflammation in metabolically healthy obesity but not normal-weight obesity.

Systemic inflammation is reported in normal-weight obesity (NWO) and metabolically healthy obesity (MHO), which may be linked to their increased cardiovascular disease (CVD) risk. Yet, drivers of this inflammation remain unclear. We characterized factors known to influence inflammatory status (i.e., intestinal permeability, adipose tissue, diet quality, microbiota), and their relationships with measured inflammation, in NWO and MHO, healthy control subjects (CON), and metabolically unhealthy obesity (MUO; N = 80; n = 20/group). Serum indicators of intestinal permeability and inflammation were assessed by ELISA and/or multiplex. Total, visceral, and percent body fat were measured with dual-energy X-ray absorptiometry (DXA). Fecal microbiota composition was assessed via 16S rRNA sequencing (n = 9-10/group). For C-reactive protein (CRP), MUO > NWO > CON (P < 0.0001). In MHO, CRP was intermediate and similar to both MUO and NWO. Lipopolysaccharide binding protein (LBP) and the ratio of LBP to soluble CD14 (sCD14) were higher in MHO and MUO vs. CON/NWO (P < 0.0001). Across correlation and regression analyses, LBP consistently displayed the strongest relationships with CRP in the entire sample (r = 0.78; ß = 0.57; P < 0.0001) and in MHO (r = 0.74; P < 0.01) but not NWO (r = 0.37; P = 0.11). Shannon index was higher in CON compared with MUO (P < 0.05) and inversely correlated with CRP in the full sample (r = -0.37; P < 0.05). These data are consistent with the notion that intestinal permeability is associated with low-grade inflammation in MHO, which could be implicated in this population's reported CVD risk.NEW & NOTEWORTHY This is the first study to our knowledge to examine biomarkers of intestinal permeability in normal-weight obesity and one of few assessing microbiota compositions in this population. Additionally, we report that individuals with metabolically healthy obesity and metabolically unhealthy obesity displayed similar evidence of intestinal permeability, which was more strongly associated with systemic inflammation than total and visceral adipose tissue mass.

A systematic review of physical activity and nutritional interventions for the management of normal weight and overweight obesity.

AIMS: Normal Weight Obesity (NWO) and Overweight Obesity (OWO) are prevalent conditions, yet knowledge of management is limited. This review aims to assess the effectiveness of physical activity and nutritional interventions in the management of NWO and OWO (together defined as BMI <30 kg/m2 with raised body fat). DATA SYNTHESIS: Clinical trials including any physical activity or nutritional interventions, published between 2012 and 2022, evaluating body fat change were selected. Seven trials met inclusion criteria, including one single arm intervention, and six RCTs. A high intensity interval training intervention (high risk of bias) had the largest effect on reducing percentage body fat (MD: -6.8%, SE: 0.06). High protein intake interventions were also found to be effective (MD: -2.8%, SE: 0.27, MD: -2.0%, SE: 0.05). These three interventions led to greater increases in fat free mass. Two energy restricted interventions resulted in the highest mean weight loss (MD: -3.10 kg, SD: 0.87 (intervention only), MD: -2.90 kg, SE: 0.06), but also loss of fat free mass, resulting in low reductions in percentage body fat (MD: -1.10%, SD: 0.57 (intervention only), MD: -0.8%, SE 0.30). There was considerable heterogeneity between studies. CONCLUSIONS: There are physical activity and nutritional interventions that could be efficacious for the management of NWO and OWO. However, there was considerable heterogeneity between studies. The most promising nutritional intervention is high protein intake and the least is energy restriction (without increased protein intake). More high-quality trials are needed to evaluate interventions, and to determine the best tools to measure adiposity.

The Normal Weight Obesity (NWO) Problem-Prevalence and Time Changes in Children and Adolescents From Kraków (Poland).

OBJECTIVES: Normal weight obesity can be associated with an increased risk of metabolic abnormalities, systemic inflammation and mortality. The main aim of the study was to analyze the changes in the prevalence of normal weight obesity in 8-18-year-olds from Kraków (Poland) between 2010 and 2020. METHODS: The study was based on two sets of cross-sectional, school-based data obtained in 2010 and 2020. Body height, weight, and fat percentage were obtained. Body mass index was calculated, and only normal-weight individuals were included. Normal weight obesity was defined as normal BMI with adiposity >85 percentile for age and sex. RESULTS: The prevalence of normal weight obesity among Polish children and adolescents has been alarming for at least the last 10 years. Depending on the sex and age, normal weight obesity was present in more than 10% up to even more than 20% of the examined population. CONCLUSIONS: Alarming numbers of Polish children and adolescents suffer from NWO and this problem seems to be present for at least the last decade. A need for a maximally universal definition and cut-offs to diagnose normal weight obesity should also be stressed, as it will be helpful in providing the best prophylaxis and help to persons already suffering from normal weight obesity.

Cardiorespiratory fitness and submaximal exercise dynamics in normal-weight obesity and metabolically healthy obesity.

PURPOSE: Cardiorespiratory fitness (CRF) is critical for cardiovascular health. Normal-weight obesity (NWO) and metabolically healthy obesity (MHO) may be at increased risk for cardiovascular disease, but a comparison of CRF and submaximal exercise dynamics against rigorously defined low- and high-risk groups is lacking. METHODS: Four groups (N = 40; 10/group) based on body mass index (BMI), body fat %, and metabolic syndrome (MetS) risk factors were recruited: healthy controls (CON; BMI 18.5-24.9 kg/m2, body fat < 25% [M] or < 35% [F], 0-1 risk factors), NWO (BMI 18.5-24.9 kg/m2, body fat ≥ 25% [M] or ≥ 35% [F]), MHO (BMI > 30 kg/m2, body fat ≥ 25% [M] or ≥ 35% [F], 0-1 risk factors), or metabolically unhealthy obesity (MUO; BMI > 30 kg/m2, body fat ≥ 25% [M] or ≥ 35% [F], 2 + risk factors). All participants completed a V ˙ O2peak test on a cycle ergometer. RESULTS: V ˙ O2peak was similarly low in NWO (27.0 ± 4.8 mL/kg/min), MHO (25.4 ± 6.7 mL/kg/min) and MUO (24.6 ± 10.0 mL/kg/min) relative to CON (44.2 ± 11.0 mL/kg/min) when normalized to total body mass (p's < 0.01), and adjusting for fat mass or lean mass did not alter these results. This same differential V ˙ O2 pattern was apparent beginning at 25% of the exercise test (PGroup*Time < 0.01). CONCLUSIONS: NWO and MHO had similar peak and submaximal CRF to MUO, despite some favorable health traits. Our work adds clarity to the notion that excess adiposity hinders CRF across BMI categories. CLINICALTRIALS: gov registration: NCT05008952.

Hidden Obesity.

This communication proposes the term "hidden obesity" to describe normal weight obesity, or increased adiposity without a corresponding increase in body mass index. It uses the concept of hidden hunger to craft semantics which will generate greater attention to this condition from all stake-holders, including policymakers and planners. The article describes simple tools which can be used to suspect and confirm the diagnosis of hidden obesity. This phenotype is very commonly seen in the south Asian population.

CUN-BAE Index as a Screening Tool to Identify Increased Metabolic Risk in Apparently Healthy Normal-Weight Adults and Those with Obesity.

BACKGROUND: Imbalanced dietary intake is related to increased adiposity, which is linked to increased metabolic risk even in the absence of obesity. BMI is traditionally used to classify body fatness and weight range, but it only considers body weight and height. The Clínica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE) equation has appeared as an additional tool to estimate adiposity considering also other relevant parameters, i.e., sex and age. OBJECTIVES: We aimed to determine whether the CUN-BAE index could estimate adiposity-related metabolic risk in apparently healthy, normoglycemic adults. METHODS: In this case-control study, men and women (18-45 y old) were classified as normal-weight (NW) [n = 20; BMI (in kg/m2) <25] or overweight-obese (OW-OB) (n = 34; BMI ≥25). The primary outcome was body fat content and clinical circulating parameters to assess by correlation analysis CUN-BAE's usefulness as a predictor of metabolic risk. In addition, transcriptomic biomarkers of lipid metabolism were analyzed in peripheral blood mononuclear cells (PBMCs) as secondary outcome indicators of metabolic impairment. Data were analyzed by correlation analysis and comparison of means. RESULTS: CUN-BAE values correlated directly with body fatness obtained by DXA (r = 0.89, P < 0.01), with classical molecular biomarkers of metabolic risk, and with PBMC gene expression of carnitine palmitoyltransferase 1A (CPT1A), sterol regulatory element binding transcription factor 1c (SREBP-1c), and fatty acid synthase (FASN), early markers of metabolic impairment (P < 0.05). Moreover, CUN-BAE allowed identification of NW individuals with excessive body fatness, who were not yet presenting obesity-related molecular alterations. In these subjects, visceral fat correlated directly with circulating glucose, triglycerides, and total and LDL cholesterol, and with triglyceride-glucose and fatty liver indexes (P < 0.05). This is indicative of a metabolically obese NW phenotype. CONCLUSIONS: Data obtained in our cohort of young normoglycemic volunteers support the use of the CUN-BAE index as a tool to estimate accurately body fat mass, but also as a first easy/effective screening tool to identify lean people with increased fat mass and increased metabolic risk.This trial was registered at clinicaltrials.gov as NCT04402697.

Association between relative fat mass, uric acid, and insulin resistance in children with chronic kidney disease.

INTRODUCTION: This cross-sectional study investigates the association between insulin resistance (IR) and serum uric acid (sUA) and relative fat (RFM) and lean mass (RLM) profiles in children with chronic kidney disease (CKD). MATERIAL AND METHODS: RLM and RFM were assessed by bioimpedance spectroscopy in 41 children and adolescents. Normal weight obesity (NWO) was defined as normal height-age body mass index and RFM >85th percentile, according to age and sex. Homeostatic model assessment of insulin resistance (HOMA-IR) level >95th percentile, according to sex and pubertal stage, and sUA >7 mg/dl were used to define IR and hyperuricemia, respectively. RESULTS: High RFM (15 patients) and NWO (7 patients) were associated with higher HOMA-IR in total (p < 0.001) and normal-weight patients (p = 0.004), respectively. RFM was positively and RLM negatively correlated to HOMA-IR (rs = 0.500, p = 0.001 and rs = -0.539, p < 0.001, respectively) and sUA (rs = 0.370, p = 0.017 and rs = -0.325, p = 0.038, respectively), while sUA was positively correlated to HOMA-IR (rs = 0.337, p = 0.031). Hyperuricemia (16 patients) was positively associated with higher RFM and HOMA-IR (p = 0.001 and p = 0.010, respectively). The correlation between sUA and HOMA-IR lost significance after adjustment for RFM. In logistic regression analysis, a 5% increase in RFM was associated with IR (11 patients) independently of the age, sex, sUA, and CKD stage in both total (OR 2.174, 95% CI 1.115-4.225) and normal-weight (OR 3.504, 95% CI 1.110-11.123) patients. CONCLUSION: Children with high RFM, including those presenting NWO, are at risk for IR regardless of CKD stage. RFM is probably the mediator of the link between sUA and IR.

Cardiometabolic risk and health behaviours in adolescents with normal-weight obesity: a systematic review.

OBJECTIVE: To analyse the presence of cardiometabolic risk factors in adolescents with normal-weight obesity (NWO), as well as to investigate health behaviours related to the phenotype. DESIGN: The study was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines and the bibliographic search was carried out in the PubMed, Scielo and ScienceDirect databases. SETTING: School, university and population. PARTICIPANTS: Adolescents between 10 and 19 years old. RESULTS: A total of eight papers were included. Most studies have found a relationship between NWO and the presence of cardiometabolic risk factors, such as high waist circumference, unfavourable lipid and glycid profile. As for health behaviours, three of the eight studies included evaluated eating habits; however, the results were not conclusive. In addition, four studies analysed the practice of physical activity or physical fitness, which was lower in NWO. CONCLUSIONS: The available evidence indicates that NWO is related to the early development of cardiometabolic changes, physical inactivity and less physical fitness in adolescents. The results also reveal the importance of early detection of the phenotype, as well as the need for further research on the associated factors to prevent future diseases. Registration (PROSPERO: CRD42020161204).

The effect of 12 weeks of euenergetic high-protein diet in regulating appetite and body composition of women with normal-weight obesity: a randomised controlled trial.

Normal-weight obesity (NWO) syndrome is associated with metabolic diseases. The present study aimed to investigate the effects of 12 weeks of a high-protein (HP) v. a standard protein (SP) diet on appetite, anthropometry and body composition in NWO women. In this clinical trial, fifty NWO women were randomly allocated to HP (n 25) or SP (n 25) diet groups. Women in the HP and SP groups consumed 25 and 15 % of their total energy intake from protein for 12 weeks. Weight, fat mass (FM), lean body mass (LBM), waist circumference (WC) and appetite were evaluated at baseline and following their 3-month intervention. After 12 weeks, the LBM was higher in HP compared with no significant changes in the SP group (mean between-group difference = 1·5 kg; 95 % CI 3·1, 0·01; effect size (d) = 0·4). Furthermore, the HP group had lower FM (mean between-group difference -1·1 kg; 95 % CI 1, -3·3; d = -0·2), body fat percentage (BFP) (mean between-group difference -2 %; 95 % CI 0·7, -5·2; d = -0·3) and WC (mean between-group difference -1·4 cm; 95 % CI 0·6, -3·6; d = -0·2) at the end of the study in comparison with the SP group. In both groups, weight and appetite were unchanged over time without significant differences between groups. Twelve weeks of euenergetic diets with different dietary protein contents resulted in no significant weight loss in women with NWO. However, an HP diet significantly improved body composition (LBM, FM, BFP and WC) in this population.

Association of adipocytokines with lipid and glycemic profiles in women with normal weight obesity.

BACKGROUND: Individuals with normal weight obesity (NWO) are predisposed to having cardiometabolic disorders. This study aims to investigate the circulating levels of vaspin, leptin and their association with glycemic and lipid profiles in women with NWO. METHODS: Forty women with body mass index (BMI) = 18.5-24.9 kg/m2 and fat mass (FM) ≥ 30% were assigned in the NWO group. Thirty age-matched women with identical BMI range, and FM < 30% (normal weight non-obese; NWNO) were considered as a control group. In addition to anthropometric measurements, glycemic and lipid profiles and circulating levels of leptin and vaspin were measured. RESULTS: The mean ± standard deviation (SD) age of participants was 28.76 ± 4.76 years in the NWO group and 29.23 ± 4.50 years in the control group. The NWO group had the higher mean serum levels of insulin (9.02 ± 4.75 vs. 6.24 ± 2.51, P = 0.009), leptin (17.31 ± 8.10 vs. 9.94 ± 4.30, P < 0.001) and homeostatic model assessment of insulin resistance (HOMA-IR) (33.77 ± 20.71 vs. 23.48 ± 10.03, P = 0.009) compared to the NWNO group. The serum level of vaspin was higher in the NWO group compared to the control group (34.82 pg/ml vs. 27.72 pg/ml, respectively, P = 0.12). In NWO group, the serum levels of leptin had positive correlation with FBS (r = 0.45, P = 0.02), insulin (r = 0.51, P = 0.008), and HOMA-IR (r = 0.46, P = 0.02) and vaspin concentration was associated with insulin (r = 0.36, P = 0.02) and HOMA-IR (r = 0.30, P = 0.06), positively. CONCLUSION: It is concluded that the concentration of insulin and HOMA-IR index were significantly higher in women with NWO compared to NWNO. Higher concentrations of leptin and vaspin in the NWO group were associated with glycemic profile.

Conjugated linoleic acid supplements preserve muscle in high-body-fat adults: A double-blind, randomized, placebo trial.

BACKGROUND AND AIMS: Conjugated linoleic acid (CLA) has been used to improve body composition in weight management. However, clinical trial results are inconsistent and limited among Asians. We aimed to investigate the effect of CLA on body composition of Chinese adults with elevated body fat percentage. METHODS AND RESULTS: In this double-blind, randomized, placebo-controlled trial, 66 Chinese adults (aged 18-45 years old, 37.9% male) with elevated body fat percentage were provided with 3.2 g/day CLA (n = 33) or 3.2 g/day placebo (sunflower oil; n = 33) for 12 weeks. Both groups received lifestyle counseling, featured with low fat and low sugar diet, and moderate physical activity. Body composition was measured using dual-energy X-ray absorptiometry at the baseline and end of the trial. Sixty-four participants finished this study. Compared with the placebo group, the CLA group showed increased trunk muscle mass (MM) (0.6 ± 1.7 vs. -0.3 ± 1.2 kg, P = 0.019). Among those with an adherence score higher than 0.80 (n = 56, 87.5%), a greater increase in both total and trunk MM was observed in the CLA group (both P < 0.05). Moreover, the effect on MM appeared to be more evident in men, those with a body mass index <25 kg/m2, or those with higher self-rated physical activity. CONCLUSIONS: In Chinese adults with elevated body fat percentage, 3.2 g/day CLA supplementation may be effective in preserving MM, especially in the trunk region. REGISTRATION: This study was registered at ClinicalTrials.gov as NCT03915808 on April 9, 2019.

Association between regional body fat and cardiovascular disease risk among postmenopausal women with normal body mass index.

AIMS: Central adiposity is associated with increased cardiovascular disease (CVD) risk, even among people with normal body mass index (BMI). We tested the hypothesis that regional body fat deposits (trunk or leg fat) are associated with altered risk of CVD among postmenopausal women with normal BMI. METHODS AND RESULTS: We included 2683 postmenopausal women with normal BMI (18.5 to <25 kg/m2) who participated in the Women's Health Initiative and had no known CVD at baseline. Body composition was determined by dual energy X-ray absorptiometry. Incident CVD events including coronary heart disease and stroke were ascertained through February 2017. During a median 17.9 years of follow-up, 291 incident CVD cases occurred. After adjustment for demographic, lifestyle, and clinical risk factors, neither whole-body fat mass nor fat percentage was associated with CVD risk. Higher percent trunk fat was associated with increased risk of CVD [highest vs. lowest quartile hazard ratio (HR) = 1.91, 95% confidence interval (CI) 1.33-2.74; P-trend <0.001], whereas higher percent leg fat was associated with decreased risk of CVD (highest vs. lowest quartile HR = 0.62, 95% CI 0.43-0.89; P-trend = 0.008). The association for trunk fat was attenuated yet remained significant after further adjustment for waist circumference or waist-to-hip ratio. Higher percent trunk fat combined with lower percent leg fat was associated with particularly high risk of CVD (HR comparing extreme groups = 3.33, 95% CI 1.46-7.62). CONCLUSION: Among postmenopausal women with normal BMI, both elevated trunk fat and reduced leg fat are associated with increased risk of CVD.

Relationship between normal weight obesity and mild cognitive impairment is reflected in cognitive-related genes in human peripheral blood mononuclear cells.

AIM: Obesity contributes to the development of mild cognitive impairment, but the potential role of normal weight obesity in this disease has not been explored in humans. The aim of the study was to reveal the relationship between normal weight obesity and mild cognitive impairment in elderly individuals. METHODS: This study consisted of 360 patients with amnestic mild cognitive impairment and 360 cognitively normal controls. Normal weight obesity was defined as having metabolic syndrome but a normal weight. Metabolic health meant having no metabolic syndrome. Reverse transcription quantitative real-time polymerase chain reaction was adopted to measure the messenger RNA expression of four cognitive-related genes (amyloid precursor protein, cyclic adenosine monophosphate-responsive element-binding protein 1, sortilin-related receptor 1, and synapsin I) in peripheral blood mononuclear cells. RESULTS: Normal weight obesity was related to a higher risk of amnestic mild cognitive impairment (odds ratio = 3.14, 95% confidence interval: 2.13-4.60). In the patients, the expression of each gene in the peripheral blood mononuclear cells was linearly related to Mini-Mental State Examination and Montreal Cognitive Assessment scores (P < 0.05). The expression of these genes in the patients with metabolic health deviated from the normal levels found in the controls (P < 0.05), and the deviations were more significant in the patients with normal weight obesity (P < 0.05). CONCLUSION: Normal weight obesity may be a potential risk factor for amnestic mild cognitive impairment in elderly. This relationship was reflected in the abnormal expression of several cognitive-related genes in peripheral blood mononuclear cells.

Ethnicity-specific cut-offs that predict co-morbidities: the way forward for optimal utility of obesity indicators.

Obesity indicators are useful clinical tools in the measurement of obesity, but it is important for clinicians to appropriately interpret their values in individuals with different ethnicities. Future research is needed to identify optimal cut-offs that can predict the occurrence of cardio-metabolic comorbidities in individuals of different ethnic descent. Assessment of more recently developed indicators like the Edmonton Obesity Staging System and visceral adipose tissue are able to appropriately identify metabolically at-risk individuals.

The BMI-adiposity conundrum in South Asian populations: need for further research.

High body fat in apparently lean individuals is a commonly described phenotype in individuals of Asian descent, but very limited consolidated scientific literature is available on this topic. This phenotype is known as 'normal-weight obesity' and may explain the large disparity between the prevalence of obesity (as measured by BMI) and diabetes that occurs in these individuals. Routine use of obesity indicators that best predict body fat content would help to identify these individuals in clinical practice. In this debate, we would like to highlight that even though fat and BMI have a good correlation, as suggested by Kryst et al. (2019), clinicians, public health researchers and policymakers should consider the use of these indicators in conjunction with each other rather than individually. Future research is needed on pathogenic mechanisms, diagnostic modalities and therapeutic options in these individuals which will help to further characterize and manage these patients appropriately.

Dietary and Biochemical Characteristics Associated with Normal-Weight Obesity.

Background: Inflammation and oxidative stress have been reported to be higher in subjects with normal weight obesity (NWO) syndrome [normal body mass index (BMI) (<25 kg/m2) but excessive body fat (for women ≥ 30% and for men ≥ 20%) according to World Health Organization (WHO) definitions]; however, it is unclear whether this is due to inadequate dietary antioxidant intake or the pathophysiology of NWO. The aim of present study was to assess the association between dietary factors and body antioxidant status with NWO syndrome in male university students. Methods: This study was a case-control study carried out on ninety age-matched male university students [30 normal weights (NW), 30 NWO and 30 overweight-obese (OB)]. A validated food frequency questionnaire (98 items) and 3-day 24-h recalls were used for dietary assessment. Total antioxidant capacity (TAC) of diet and serum and high-sensitive C-reactive protein (hs-CRP) concentrations were also measured. Results: Dietary intake of fruits (frequency factor (FF) = 2.3 vs 2.9, p < 0.05), legumes (FF = 0.7 vs 1.3, p < 0.01), nuts and seeds (FF = 0.4 vs 0.8, p < 0.05), beta-cryptoxanthin (p < 0.05), lycopene (p < 0.05) and serum TAC levels (p < 0.01) were significantly lower in NWO compared to the NW group. No significant differences in these parameters were observed between NWO and OB group. A significant negative correlation was observed between serum TAC levels and BMI (r = -0.57, p < 0.001) and body fat percent (r = -0.52, p < 0.001). Conclusions: This study shows that NWO male subjects consume lower amounts of dietary antioxidants and share the same low body antioxidant status as obese individuals, although they appear lean.

Normal-weight obesity frequency in the Central European urban adult female population of Brno, Czech Republic.

OBJECTIVES: The universally recognized indicator of nutritional status, BMI, has some shortcomings, especially in detecting overweight and obesity. A relatively recently introduced normal weight obesity (NWO) describes a phenomenon when individuals are found to have normal weight as indicated by BMI but have an elevated percentage of body fat. Normal weight obese individuals face a higher risk of developing metabolic syndrome, cardiometabolic dysfunction and have higher mortality. No studies have been previously performed which would map NWO in Brno, Czech Republic. METHODS: In a sample of 100 women from Brno, we assessed the percentage of normal weight obese individuals using bioelectric impedance analysis (BIA) - three different analyzers were utilized: Tanita BC-545 personal digital scale, InBody 230 and BodyStat 1500MDD. Also, a caliperation method was used to estimate body fat percentage. Various body fat percentage cut-off points were used according to different authors. RESULTS: When the 30% body fat (BF) cut-off was used, up to 14% of the women in our sample were found to be normal weight obese. When the sum of skinfolds or the 35% BF cut-off point are selected as a criterion for identifying normal weight obesity (NOW), only 1 of 100 examined women was identified as normal weight obese; at the 35% BF cut-off, BodyStat analyzer categorized no women as normal weight obese. Also, when the 30% BF or 66th percentile BF cut-off points were utilized, BodyStat identified pronouncedly fewer women from our sample to be normal-weight obese than the two other analyzers. CONCLUSIONS: On a pilot sample of Czech women, we demonstrated that depending on the selected cut-off (there is no clear agreement on cut-off points in literature), up to 14% of the examined women were found to be normal weight obese.

Prevalence and cardiometabolic risks of normal weight obesity in Chinese population: A nationwide study.

BACKGROUND AND AIMS: Several studies have reported increased cardiovascular risks in normal weight obesity (NWO) populations. We aimed to investigate the prevalence of NWO and its relationships with cardiometabolic risks in Chinese patients. METHODS AND RESULTS: The data were from the 2007-2008 China National Diabetes and Metabolic Disorders Study. The body fat (BF) was measured using the biological impedance method. NWO was defined as a normal BMI (18.5-23.9 kg/m2) but with excess BF% (BF% ≥ 24% for men and ≥33% for women). 23,748 people (9633 males and 14,115 females) were enrolled and the prevalence of NWO was 9.5% for men, 6.06% for women. The prevalence risks of diabetes (odds ratio [OR]1.519, 95% confidence interval [CI] 1.262-1.828), Framingham risk score (FRS) ≥10% (OR 1.973, 95% CI 1.596-2.439), hypertension (OR 1.525, 95% CI 1.333-1.745), and metabolic syndrome Mets (OR 2.175, 95% CI 1.920-2.463) significantly increased in the NWO group compared with the normal group. Subgroup analyses showed that, after ruling out participants with abnormal waist circumference, the male group had similar findings to the overall population; but in the female group, the prevalence risks of FRS ≥10%, hypertension, and Mets increased, although the risk of diabetes did not. CONCLUSION: NWO is in a relatively high prevalence in Chinese population, and the prevalence of NWO is higher in Chinese men compared to Chinese women. Cardiometabolic risks significantly increase in an NWO population, and such risks persist after excluding the effect of abdominal obesity.

Association between normal-weight obesity and bone mineral density in older Korean adults: A population-based cross-sectional study.

The effects of normal-weight obesity, which is defined as having a high level of body fat despite a normal body mass index, on the health of bones in older adults are poorly understood. This cross-sectional study examined the relationship between normal-weight obesity and bone mineral density in Korean adults aged 50 years or more (2815 men and 2744 women) from the 2008-2011 Korea National Health and Nutrition Examination Surveys. Between the ages of 50 and 69 years, individuals with normal-weight obesity had a higher risk of low bone mineral density (odds ratio = 1.596, 95 % confidence interval = 1.189-2.141, p = 0.002) compared with individuals with normal-weight non-obesity. However, no significant association between normal-weight obesity and bone mineral density was observed among people between the ages of 70 and 89 years. The study findings support the clinical significance of normal-weight obesity as a proxy biomarker to identify in primary care settings people who are at increased risk of developing osteoporosis at an early stage of aging.

Lipidomic perturbations of normal-weight adiposity phenotypes and their mediations on diet-adiposity associations.

BACKGROUND & AIMS: Normal-weight obesity (NWO) and normal-weight central obesity (NWCO) have been linked to higher cardiometabolic risks, but their etiological bases and attributable dietary factors remain unclear. In this study we therefore aimed to identify lipidomic signatures and dietary factors related to NWO and NWCO and to explore the mediation associations of lipids in diet-adiposity associations. METHODS: Using a high-coverage targeted lipidomic approach, we quantified 1245 serum lipids in participants with NWO (n = 150), NWCO (n = 150), or propensity-score-matched normal-weight controls (n = 150) based on the Regional Ethnic Cohort Study in Northwest China. Consumption frequency of 28 major food items was recorded using a food frequency questionnaire. RESULTS: Profound lipidomic perturbations of NWCO relative to NWO were observed, and 249 (dominantly glycerolipids) as well as 48 (dominantly glycerophospholipids) lipids were exclusively associated with NWCO or NWO. Based on strong lipidomic signatures identified by a LASSO model, phospholipid biosynthesis was the top enriched pathway of NWCO, and sphingolipid metabolism was the top pathway of NWO. Remarkably, sphingolipids were positively associated with NWO and NWCO, but lyso-phosphatidylcholines were negatively associated with them. Rice, fruit juice, and carbonated drink intakes were positively associated with the risk of NWCO. Both global and individual lipidomic signatures, including SE(28:1_22:6) and HexCer(d18:1/20:1), mediated these diet-NWCO associations (mediation proportion: 15.92%-26.10%). CONCLUSIONS: Differential lipidomic signatures were identified for overall and abdominal adiposity accumulation in normal-weight individuals, underlining their core mediation roles in dietary contributions to adiposity deposition.