Metabolic assessment of female chronic dieters with either normal or low resting energy expenditures

Long-Term Weight Loss and Metabolic Health in Adults Concerned With Maintaining or Losing Weight: Findings From NHANES

More than two-thirds of American adults are overweight or obese, with many attempting to lose weight to avoid adverse health outcomes and improve well-being. Achieving long-term weight loss (LTWL) success, defined as reaching at least a 5% to 10% weight loss goal, is challenging, yet important for overall metabolic health. It is currently unclear whether achieving higher thresholds of LTWL is associated with improved health. Therefore, the purpose of this study was to examine the association between LTWL thresholds (5%-9.9%, 10%-14.9%, 15%-19.9%, ≥20%) and metabolic health (metabolic syndrome and metabolic risk z score) among 7670 US adult respondents to the National Health and Nutrition Examination Survey (2007-2014) who were overweight or obese (past or present), were not underweight in the past year, not pregnant, and attempting to lose or maintain weight. A subsample of 3362 participants was used in the analysis of the metabolic risk z score. Multivariable regression models were constructed adjusting for covariates. Results indicate that the lowest and the 2 highest LTWL thresholds were related to lower odds for metabolic syndrome; for example, greater than or equal to 20% LTWL (odds ratio=0.52; 95% CI, 0.23-0.44; P<.001). All LTWL thresholds were significantly associated with the metabolic risk z score, with the largest effect among the 2 highest LTWL thresholds, that is, 15% to 19.9% LTWL (β=-0.45; 95% CI, -0.54 to -0.36; P<.001) and greater than or equal to 20% LTWL (β=-0.35; 95% CI, -0.53 to -0.17; P<.001). In conclusion, although achieving the currently recommended LTWL target was related to improved metabolic health, the 15% LTWL threshold was associated with more favorable outcomes.

Sex differences in the association between dietary restraint, insulin resistance and obesity

BACKGROUND & AIMS

Restrained food consumption may alter metabolic function and contribute to eventual weight gain; however, sex differences in these relationships have not been assessed. The objective of this study was to examine the relationship between restrained eating and insulin resistance and the influence of body mass index and sex on this relationship in a large community sample of both men and women. We hypothesized that restrained eating would be related to insulin resistance and this relationship would be influenced by sex and body mass index.

METHODS

In this cross-sectional, observational study, we studied 487 individuals from the community (men N = 222, women N = 265), who ranged from lean (body mass index 18.5-24.9 kg/m(2), N = 173), overweight (body mass index 25-29.9 kg/m(2), N = 159) to obese (body mass index >30 kg/m(2), N = 155) weight categories. We assessed restrained eating using the Dutch Eating Behavior Questionnaire and obtained fasting morning plasma insulin and glucose on all subjects.

RESULTS

In men, but not in women, restrained eating was related to homeostatic model assessment of insulin resistance (HOMA-IR) (p < 0.0001). Furthermore, HOMA-IR was significantly higher in men who were high- versus low-restrained eaters (p = 0.0006).

CONCLUSIONS

This study is the first to report sex differences with regard to the relationship between restrained eating and insulin resistance. Our results suggest that high restrained eating is associated with insulin resistance in men but not in women.

Gestational weight gain as a predictor of longitudinal body mass index transitions among socioeconomically disadvantaged women

BACKGROUND

Socioeconomically disadvantaged women are at greater risk for gestational weight gain and postpartum weight retention compared to socioeconomically advantaged women. This study examines the effect of gestational weight gain on body mass index (BMI) transitions 5 years after pregnancy in socioeconomically disadvantaged women.

METHODS

Gestational weight gain was assessed in 2136 postpartum women participating in the Fragile Families and Child Well-being study who experienced full-term, singleton gestations. Longitudinal BMI transitions were defined as a change or stability in BMI category between two time points: BMI before the index pregnancy and BMI 5 years after the index pregnancy. Logistic regression models estimated the association between gestational weight gain and longitudinal BMI transitions, controlling for health before the index pregnancy, pregnancy history, and sociodemographic characteristics.

RESULTS

Excessive gestational weight gain was related to transitioning to a higher BMI category 5 years after the index pregnancy. Compared to white women, black and Hispanic women were more likely to transition or maintain a higher BMI category. Pregnancy history (i.e., parity at index pregnancy, interim pregnancy) and public assistance participation were associated with transitioning to a higher BMI category.

CONCLUSIONS

Among socioeconomically disadvantaged women, excessive gestational weight gain is related to transitioning to, but not maintaining, a higher weight category 5 years after the index pregnancy. Black and Hispanic women who are also socioeconomically disadvantaged and overweight or obese before conception may benefit from preconception or postpartum counseling about the long-term effect of gaining excessive weight during pregnancy and in the years immediately after childbirth.

Stress-induced eating in restrained eaters may not be caused by stress or restraint

Restrained eaters tend to increase and unrestrained eaters to decrease their food intake when stressed. This relationship, though robust, does not appear to be caused by restrained eating or by stress per se. For restraint, evidence indicates that none of the common operationalizations of restraint can account for restraint-related effects that have been examined to date. It is therefore unlikely that restraint is responsible for stress-induced eating in restrained eaters. Rather, behavioral and physiological data suggest that restrained eating may be a proxy risk factor for vulnerability to weight gain. For stress, a variety of minimally stressful perturbations (e.g. non-threatening cognitive loads) have been shown to elicit increased intake in restrained eaters. Thus, the negative affect created by manipulations used to create stress (e.g. scary movies, failure at a task) does not appear to be necessary to provoke overeating. An adequate explanation for stress-induced eating in restrained eaters remains elusive.

Leptin response to short-term fasting in sympathectomized men: role of the SNS

We studied plasma leptin levels in six people with high-lesion spinal cord injury [SCI; body mass index (BMI) 25.9 +/- 1.5 kg/m(2), age 37 +/- 3.0 yr] and six able-bodied (AB) controls (BMI 29.1 +/- 1.9 kg/m(2), age 35 +/- 3.5 yr) before and after 12, 24, and 36 h of fasting. The plasma leptin levels significantly decreased during 36 h fasting by 48.8 +/- 4.5% (pre: 11.3 +/- 2.3, post: 6.2 +/- 1.5 ng/ml) and 38.6 +/- 7.9% (pre: 7.6 +/- 5.0, post: 4.2 +/- 1.0 ng/ml) in SCI and AB, respectively. Plasma leptin started to decrease at 24 h of fasting in the SCI group, whereas plasma leptin started to decrease at 12 h of fasting in the AB group. The current study demonstrated that plasma leptin decreased with fasting in both SCI and AB groups, with the leptin decrease being delayed in the SCI group. The delayed leptin response to fasting in the SCI group may be because of increased fat mass (%body fat, SCI: 33.8 +/- 3.0, AB: 24.1 +/- 2.9) and sympathetic nervous system dysfunction.

Factors correlated with hypermetabolism in patients with amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a severe disease characterized by neurogenic amyotrophy and degeneration of upper and lower motor neurons. Although ALS patients usually experience reductions in fat-free mass (FFM), hypermetabolism via an undetermined source has also been reported.

OBJECTIVE

The objective was to clarify the metabolic level of ALS patients.

DESIGN

We measured the resting energy expenditure (REE) of 62 patients (32 men and 30 women) with ALS and investigated the factors correlated with metabolic level. Nutritional evaluation included bioelectrical impedance analysis, indirect calorimetry, and calculation of the body mass index. Neurologic assessment included an evaluation of peripheral and central neurologic deficit. Forced vital capacity was measured and smoking status was noted. A complete blood cell count was made and thyroid hormone and C-reactive protein concentrations were measured.

RESULTS

Patients were hypermetabolic, by an average of approximately 10% more than in a reference healthy population. FFM, age, and the neutrophil count were significantly associated with REE. The only variable that contributed to the prediction of REE, REE/Z100 kHz (bioimpedance at 100 kHz), REE adjusted for FFM, or the ratio of measured REE to calculated REE was the neutrophil count, which explained only a small percentage of variance in the multiple regression analysis. Hypermetabolism was not associated with a reduction in respiratory function, tobacco use, hyperthyroidism, spasticity and fasciculation intensities, or infection.

CONCLUSIONS

Our study corroborates the surprising finding that ALS patients are hypermetabolic. FFM, age, sex, manual muscular testing, the modified Norris limb score, weight, and an increase in circulating neutrophil counts correlated with the hypermetabolic state. Other factors may play a role in pathophysiologic processes that involve mitochondrial energy production or even sympathoadrenergic activation.