Energy expenditure in lean and obese women: the role of posture allocation

Obesity occurs when energy intake exceeds energy expenditure over an extended period of time. Low resting metabolic rate (RMR), or expending less energy at rest than persons of equivalent body size, is considered a risk factor for weight gain leading to obesity. However, because obese persons tend to have greater lean mass (LM) as well as fat mass (FM) than do lean individuals, absolute RMR tends to be higher, rendering the detection of initial impairments in RMR difficult. Purposes of this study were to determine resting energy expenditure (REE) in lean and obese women who were matched for LM and investigate differences in activity energy expenditure (AEE) and daily patterns of activity between the two groups. Twenty healthy, nonsmoking, pre-menopausal women (10 lean and 10 obese, matched for LM) participated in this 14-day observational study on free-living energy balance. REE was measured by indirect calorimetry, AEE and total energy expenditure (TEE) were calculated using doubly labeled water, and activity patterns were investigated using two activity monitors. REE was similar in the obese vs. lean women (1601 +/- 109 vs. 1505 +/- 109 kcal/d, respectively, P=.12, adjusting for LM and FM). TEE and AEE were both lower in the obese women (2,414 +/- 126 vs. 2,698 +/- 126 kcal/d, P=.02; 550 +/- 133 vs. 943 +/- 133 kcal/d, P=.09; respectively, adjusting for LM). Obese women sat 2.5 hours more each day (12.7 +/- 3.2 h vs. 10.1 +/- 2.0 h, P\u3c.05), stood 2 hours less (2.7 +/- 1.0 h vs. 4.7 +/- 2.2 h, P=.02) and spent half as much time being physically active than lean women (2.6 +/- 1.5 h vs. 5.4 +/- 1.9 h, P=.002). Findings from this study indicate that REE was not lower in this group of obese women; however, they were more sedentary and expended less energy in activity than the lean women. If the obese women adopted the activity patterns of the lean women, including modification of posture allocation, an additional 300 kcal could be expended every day

Weight gain reveals dramatic increases in skeletal muscle extracellular matrix remodeling

Context: In animal models of obesity, chronic inflammation and dysregulated extracellular matrix remodeling in adipose tissue leads to insulin resistance. Whether similar pathophysiology occurs in humans is not clear. Objective: The aim of this study was to test whether 10% weight gain induced by overfeeding triggers inflammation and extracellular matrix remodeling (gene expression, protein, histology) in skeletal muscleandsc adipose tissue in humans.Wealso investigated whether such remodelingwas associated with an impaired metabolic response (hyperinsulinemic-euglycemic clamp). Design, Setting, Participants, and Intervention: Twenty-nine free-living males were fed 40% over their baseline energy requirements for 8 weeks. Results: Ten percent body weight gain prompted dramatic up-regulation of a repertoire of extracellular matrix remodeling genes in muscle and to a lesser degree in adipose tissue. The amount of extracellular matrix genes in the muscle were directly associated with the amount of lean tissue deposited during overfeeding. Despite weight gain and impaired insulin sensitivity, there was no change in local adipose tissue or systemic inflammation, but there was a slight increase in skeletal muscle inflammation. Conclusion:Wepropose that skeletal muscle extracellular matrix remodeling is another feature of the pathogenic milieu associated with energy excess and obesity, which, if disrupted, may contribute to the development of metabolic dysfunction. © 2014 by the Endocrine Society

Is Overweight in Stunted Preschool Children in Cameroon Related to Reductions in Fat Oxidation, Resting Energy Expenditure and Physical Activity?

Recent studies suggest that early modifications in metabolic pathways and behaviour, leading to energy conservation and reduced linear growth, could represent adaptations to nutritional constraints during foetal life and infancy. Impaired fat oxidation, low resting energy expenditure and reduced physical activity, resulting from these adaptations, could facilitate fat storage and development of overweight in growth-retarded children that consume more energy-dense food. This study aims at assessing whether: (1) dual-burden preschool children (simultaneously stunted and overweight) of Yaounde (Cameroon) have low birth-weight (indicator of foetal undernutrition) and reductions in fat oxidation, resting energy expenditure (REE) and physical activity, (2) fat oxidation, REE and physical activity are associated with foetal growth.162 children (24-72 months) were considered: 22 stunted-overweight (SO), 40 stunted (S), 41 overweight (O), and 59 non stunted-non overweight (NSNO). Nutritional status and body composition were assessed using anthropometry and multifrequency bioimpedance analysis. Fasting respiratory quotient (RQ) and REE were measured by indirect calorimetry. Physical activity was determined using accelerometers, food questionnaires were used for diet assessment and birth-weight was noted. Mean RQs and REE (weight adjusted) did not differ between stunted children (SO and S) and non-stunted children (O and NSNO). SO and S children spent more time in sedentary activities than O children (p = 0.01 and p = 0.02, respectively) and less time in moderate-to-vigorous activities than NSNO children (p = 0.05 and p = 0.04, respectively). SO children's diet was less diverse (p = 0.01) with less animal products (p = 0.006). Multiple linear regressions model revealed that birth-weight is predictive of RQ (β = 0.237, p<0.01, R(2) = 0.08).This study showed that growth retardation in stunted-overweight children could be associated with postnatal nutritional deficiencies. Overweight in stunted children could be associated with reduced physical activity in the context of nutrition transition. High birth-weight was a predictor of reduced lipid oxidation, a risk factor of fat deposition

Muscle activity and inactivity periods during normal daily life

Recent findings suggest that not only the lack of physical activity, but also prolonged times of sedentary behaviour where major locomotor muscles are inactive, significantly increase the risk of chronic diseases. The purpose of this study was to provide details of quadriceps and hamstring muscle inactivity and activity during normal daily life of ordinary people. Eighty-four volunteers (44 females, 40 males, 44.1&plusmn;17.3 years, 172.3&plusmn;6.1 cm, 70.1&plusmn;10.2 kg) were measured during normal daily life using shorts measuring muscle electromyographic (EMG) activity (recording time 11.3&plusmn;2.0 hours). EMG was normalized to isometric MVC (EMGMVC) during knee flexion and extension, and inactivity threshold of each muscle group was defined as 90% of EMG activity during standing (2.5&plusmn;1.7% of EMGMVC). During normal daily life the average EMG amplitude was 4.0&plusmn;2.6% and average activity burst amplitude was 5.8&plusmn;3.4% of EMGMVC (mean duration of 1.4&plusmn;1.4 s) which is below the EMG level required for walking (5 km/h corresponding to EMG level of about 10% of EMGMVC). Using the proposed individual inactivity threshold, thigh muscles were inactive 67.5&plusmn;11.9% of the total recording time and the longest inactivity periods lasted for 13.9&plusmn;7.3 min (2.5&ndash;38.3 min). Women had more activity bursts and spent more time at intensities above 40% EMGMVC than men (p&lt;0.05). In conclusion, during normal daily life the locomotor muscles are inactive about 7.5 hours, and only a small fraction of muscle\u27s maximal voluntary activation capacity is used averaging only 4% of the maximal recruitment of the thigh muscles. Some daily non-exercise activities such as stair climbing produce much higher muscle activity levels than brisk walking, and replacing sitting by standing can considerably increase cumulative daily muscle activity

Energy expenditure in lean and obese women: the role of posture allocation

Obesity occurs when energy intake exceeds energy expenditure over an extended period of time. Low resting metabolic rate (RMR), or expending less energy at rest than persons of equivalent body size, is considered a risk factor for weight gain leading to obesity. However, because obese persons tend to have greater lean mass (LM) as well as fat mass (FM) than do lean individuals, absolute RMR tends to be higher, rendering the detection of initial impairments in RMR difficult. Purposes of this study were to determine resting energy expenditure (REE) in lean and obese women who were matched for LM and investigate differences in activity energy expenditure (AEE) and daily patterns of activity between the two groups. Twenty healthy, nonsmoking, pre-menopausal women (10 lean and 10 obese, matched for LM) participated in this 14-day observational study on free-living energy balance. REE was measured by indirect calorimetry, AEE and total energy expenditure (TEE) were calculated using doubly labeled water, and activity patterns were investigated using two activity monitors. REE was similar in the obese vs. lean women (1601 +/- 109 vs. 1505 +/- 109 kcal/d, respectively, P=.12, adjusting for LM and FM). TEE and AEE were both lower in the obese women (2,414 +/- 126 vs. 2,698 +/- 126 kcal/d, P=.02; 550 +/- 133 vs. 943 +/- 133 kcal/d, P=.09; respectively, adjusting for LM). Obese women sat 2.5 hours more each day (12.7 +/- 3.2 h vs. 10.1 +/- 2.0 h, P<.05), stood 2 hours less (2.7 +/- 1.0 h vs. 4.7 +/- 2.2 h, P=.02) and spent half as much time being physically active than lean women (2.6 +/- 1.5 h vs. 5.4 +/- 1.9 h, P=.002). Findings from this study indicate that REE was not lower in this group of obese women; however, they were more sedentary and expended less energy in activity than the lean women. If the obese women adopted the activity patterns of the lean women, including modification of posture allocation, an additional 300 kcal could be expended every day.</p

Influence of Parents\u27 Eating Behaviors and Child Feeding Practices on Children\u27s Weight Status

OBJECTIVE: To investigate the effects of mothers\u27 and fathers\u27 eating behaviors, child feeding practices, and BMI on percentage body fat and BMI in their children.RESEARCH METHODS AND PROCEDURES: Four hundred fifty-eight parents (239 mothers, 219 fathers) were asked to complete two questionnaires: the Three-Factor Eating Questionnaire and the Child Feeding Questionnaire, which measure dimensions of parent eating behavior and child feeding practices, respectively. Parent BMI was calculated from self-reported height and weight; children\u27s measures included BMI and percentage fat assessed by DXA. Regression analyses were used to analyze relationships between parents\u27 BMI and questionnaire scores and children\u27s weight status.RESULTS: One hundred forty-three mothers and 68 fathers returned questionnaires, representing parents of 148 children 3 to 5 years old (78 boys). Children\u27s weight was related to mothers\u27 BMI, but not fathers\u27. Girls had a greater BMI if either parent reported being overweight as a child, and both girls and boys were likely to be overweight if their mothers believed they had risky eating habits (fussiness, eating too much, etc.). Girls with fathers who were more controlling had a higher percentage fat; these fathers were also more concerned about their daughters\u27 future health.DISCUSSION: Mothers exert a strong influence over their children\u27s weight and seem to be more concerned about their children\u27s eating behaviors; however, fathers play a role in imposing child feeding practices. Gender bias may be present in child feeding, as suggested by dissimilar effects of parent practices on the weight status of girls vs. boys. Fathers should be included in future studies analyzing parent feeding practices and children\u27s weight outcome

Can Increased Muscle ROS Scavenging Keep Older Animals Young and Metabolically Fit?

Insulin resistance and lipid accumulation occur with aging, perhaps due to mitochondrial dysfunction. In this issue of Cell Metabolism (Lee et al., 2010), older mice overexpressing mitochondrial targeted catalase had reduced muscle mitochondrial oxidative damage, lower intramuscular lipid, and improved insulin sensitivity, suggesting that enhanced ROS scavenging prevents age-associated mitochondrial impairments and insulin resistance

Effect of short-term thyroxine administration on energy metabolism and mitochondrial efficiency in humans.

The physiologic effects of triiodothyronine (T3) on metabolic rate are well-documented; however, the effects of thyroxine (T4) are less clear despite its wide-spread use to treat thyroid-related disorders and other non-thyroidal conditions. Here, we investigated the effects of acute (3-day) T4 supplementation on energy expenditure at rest and during incremental exercise. Furthermore, we used a combination of in situ and in vitro approaches to measure skeletal muscle metabolism before and after T4 treatment. Ten healthy, euthyroid males were given 200 µg T4 (levothyroxine) per day for 3 days. Energy expenditure was measured at rest and during exercise by indirect calorimetry, and skeletal muscle mitochondrial function was assessed by in situ ATP flux ((31)P MRS) and in vitro respiratory control ratio (RCR, state 3/state 4 rate of oxygen uptake using a Clark-type electrode) before and after acute T4 treatment. Thyroxine had a subtle effect on resting metabolic rate, increasing it by 4% (p = 0.059) without a change in resting ATP demand (i.e., ATP flux) of the vastus lateralis. Exercise efficiency did not change with T4 treatment. The maximal capacity to produce ATP (state 3 respiration) and the coupled state of the mitochondria (RCR) were reduced by approximately 30% with T4 (p = 0.057 and p = 0.04, respectively). Together, the results suggest that T4, although less metabolically active than T3, reduces skeletal muscle efficiency and modestly increases resting metabolism even after short-term supplementation. Our findings may be clinically relevant given the expanding application of T4 to treat non-thyroidal conditions such as obesity and weight loss