Calcium plus vitamin D supplementation and fat mass loss in female very low-calcium consumers: potential link with a calcium-specific appetite control.

This randomized, double-blind, placebo-controlled study was conducted to compare the effect of a 15-week weight-reducing programme ( -2900 kJ/d) coupled with a calcium plus vitamin D (calcium+D) supplementation (600 mg elemental calcium and 5 microg vitamin D, consumed twice a day) or with a placebo, on body fat and on spontaneous energy/macronutrient intake. Sixty-three overweight or obese women (mean age 43 years, mean BMI 32 kg/m2) reporting a daily calcium intake < 800 mg participated in present study. Anthropometric variables, resting energy expenditure and spontaneous energy intake were measured before and after the 15-week programme. The calcium+D supplementation induced no statistically significant increase in fat mass loss in response to the programme. However, when analyses were limited to very low-calcium consumers only (initial calcium intake < or =600 mg/d, n 7 for calcium+D, n 6 for placebo), a significant decrease in body weight and fat mass (P < 0.01) and in spontaneous dietary lipid intake (P < 0.05) was observed in the calcium+D but not in the placebo group. In very low-calcium consumers, change in fat mass was positively correlated with change in lipid intake. During the weight-reducing programme, a calcium+D supplementation was necessary in female overweight/obese very low-calcium consumers to reach significant fat mass loss that seemed to be partly explained by a decrease in lipid intake. We propose that this change in lipid intake could be influenced by a calcium-specific appetite control.

Multivitamin and dietary supplements, body weight and appetite: results from a cross-sectional and a randomised double-blind placebo-controlled study.

Two studies were conducted to compare characteristics of consumers and non-consumers of vitamin and/or dietary supplements (study 1) and to assess the effect of a multivitamin and mineral supplementation during a weight-reducing programme (study 2). Body weight and composition, energy expenditure, and Three-Factor Eating Questionnaire scores were compared between consumers and non-consumers of micronutrients and/or dietary supplements in the Québec Family Study (study 1). In study 2, these variables and appetite ratings (visual analogue scales) were measured in forty-five obese non-consumers of supplements randomly assigned to a double-blind 15-week energy restriction ( - 2930 kJ/d) combined with a placebo or with a multivitamin and mineral supplement. Compared with non-consumers, male consumers of vitamin and/or dietary supplements had a lower body weight (P < 0.01), fat mass (P < 0.05), BMI (P < 0.05), and a tendency for greater resting energy expenditure (P = 0.06). In women, the same differences were observed but not to a statistically significant extent. In addition, female supplements consumers had lower disinhibition and hunger scores (P < 0.05). In study 2, body weight was significantly decreased after the weight-loss intervention (P < 0.001) with no difference between treatment groups. However, fasting and postprandial appetite ratings were significantly reduced in multivitamin and mineral-supplemented women (P < 0.05). Usual vitamin and/or dietary supplements consumption and multivitamin and mineral supplementation during a weight-reducing programme seems to have an appetite-related effect in women. However, lower body weight and fat were more detectable in male than in female vitamin and/or dietary supplements consumers.

Does the energy expenditure status in obstructive sleep apnea favour a positive energy balance?

PURPOSE: The effect of the obstructive sleep apnea syndrome on energy expenditure is controversial. The objective of this study was to assess the relationship between 24-hr energy expenditure or sleeping metabolic rate and features of the obstructive sleep apnea. METHODS: Twenty-four apneic men took part in this cross-sectional study and were classified in quartiles of nocturnal desaturation severity, i.e. of percentage total sleep time with SaO2 < 90% determined with polysomnography. 24-hr energy expenditure and sleeping metabolic rate were measured with a whole body indirect calorimetry (respiratory chamber), and body composition by hydrodensitometry. During the stay in the respiratory chamber, urine was collected to assess catecholamine concentration and percentage recording time with SaO2 < 90% (%TRT SaO2 < 90%) was measured with nocturnal oximetry. RESULTS: Mean fat free mass and fat mass were greater in quartile 4 than in quartile 1 (P < 0.05). %TRT SaO2 < 90% was higher in quartile 4 than in other quartiles (P < 0.0001). 24-hr energy expenditure and sleeping metabolic rate were similar among quartiles. However, when expressed on a per kg body weight basis (kcal/kg), these variables were negatively correlated with the %TRT SaO2 < 90% in the whole group (r = -0.46 and -0.48, respectively, P < 0.05). %TRT SaO2 < 90% was found to be a predictor of sleeping metabolic rate which explained, together with fat mass and fat free mass, 86% of this variance (P < 0.05). CONCLUSION: In apneic men energy expenditure relative to body weight decreases with increasing severity of oxygen desaturation which could favour a positive energy balance.

Supplementation with calcium + vitamin D enhances the beneficial effect of weight loss on plasma lipid and lipoprotein concentrations.

BACKGROUND: Adequate calcium intake can have a favorable effect on some metabolic variables. OBJECTIVE: The objective of the study was to determine the effects of daily calcium intake and of supplementation with calcium and vitamin D (calcium+D) during a weight-loss intervention on blood pressures, plasma lipid and lipoprotein concentrations, and glucose and insulin concentrations in low calcium consumers. DESIGN: Healthy, overweight or obese women (n = 63) with a daily calcium intake of < 800 mg/d were randomly assigned in a double-blind manner to 1 of 2 groups: the group consuming 2 tablets/d of a calcium + vitamin D supplement (600 mg elemental calcium and 200 IU vitamin D/tablet) or the group consuming placebo; both groups observed a 700 kcal/d energy restriction. These 63 women then completed a 15-wk weight-loss intervention. RESULTS: Initial daily calcium intake was significantly correlated with plasma HDL cholesterol (r = 0.41, P < 0.001) and with 2-h postload glycemia (r = -0.29, P < 0.05) during an oral-glucose-tolerance test, independent of fat mass and waist circumference. After the 15-wk intervention, significantly greater decreases in total:LDL and LDL:HDL (P < 0.01 for both) and of LDL cholesterol (P < 0.05) were observed in the calcium+D group than in the placebo group. The differences in total:HDL and LDL:HDL were independent of changes in fat mass and in waist circumference. A tendency for more beneficial changes in HDL cholesterol, triacylglycerol, and total cholesterol was also observed in the calcium+D group (P = 0.08). CONCLUSION: Consumption of calcium+D during a weight-loss intervention enhanced the beneficial effect of body weight loss on the lipid and lipoprotein profile in overweight or obese women with usual low daily calcium intake.

The effect of obesity on chronic respiratory diseases: pathophysiology and therapeutic strategies.

Sedentary lifestyles and increased pollution brought about by industrialization pose major challenges to the prevention of both obesity and chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD), asthma, obstructive sleep apnea and obesity hypoventilation syndrome. Obesity has emerged as an important risk factor for these respiratory diseases, and in many instances weight loss is associated with important symptomatic improvement. Moreover, obesity may influence the development and presentation of these diseases. In this article, we review the current understanding of the influence of obesity on chronic respiratory diseases and the clinical management of obesity concurrent with asthma, COPD, obstructive sleep apnea or obesity hypoventilation syndrome.

Energy expenditure from physical activity and the metabolic risk profile at menopause.

PURPOSE: A sedentary lifestyle and visceral obesity are important risk factors for Type 2 diabetes and the development of cardiovascular disease, two conditions that are prevalent in women after menopause. The aim of this study was to assess the relationship between daily energy expenditure from moderate to intense physical activity and several metabolic parameters in postmenopausal women not receiving hormone therapy (HT) and to verify whether these associations are independent of the accumulation of visceral adipose tissue (AT). METHODS: Daily energy expenditure and frequency of participation in physical activity (kcal.kg(-1).15 min(-1)) were measured from a 3-d activity diary in 118 postmenopausal women (56 +/- 4 yr; 29 +/- 6 kg.m(-2)). Daily activities for each 15-min period during 24 h were categorized according to their intensity on a 1-9 scale. Category 1 indicated very low energy expenditure such as sleeping, and category 9 indicated very high energy expenditure such as running. Energy expenditure corresponding to categories 6-9 (EE6-9) was examined in relation to the metabolic risk profile. RESULTS: EE6-9 was negatively and significantly associated with body mass index (BMI) (r = -0.22, P < 0.05) and visceral AT accumulation (r = -0.18, P < 0.05). Partial correlation analyses adjusted for visceral AT showed that EE6-9 was significantly associated with systolic blood pressure (r = -0.22, P < 0.05), plasma concentrations of HDL-cholesterol (chol) (r = 0.23, P < 0.05), HDL2-chol (r = 0.22, P < 0.05), fasting glucose (r = -0.24, P < 0.05), and fasting C-peptide (r = -0.24, P = or <0.05). EE6-9 was also associated with insulin sensitivity as measured by the hyperinsulinemic-euglycemic clamp (r = 0.27, P < 0.01). CONCLUSIONS: Higher engagement in physical activity (EE6-9) is associated with a lower BMI and visceral AT accumulation and with a healthier metabolic profile in postmenopausal women. Furthermore, the associations between EE6-9 and some metabolic parameters appear to be independent of visceral AT accumulation.

Energy intake during a typical Himalayan trek.

People taking part in commercial treks are exposed to high altitude (HA) while eating ad libitum, a situation that has been related to under eating and body weight loss. We investigated this phenomenon in westerners taking part in a typical Himalayan trek. Body weight, energy intake (EI), macronutrient composition of the diet, and acute mountain sickness symptoms (AMS) were measured in seven healthy individuals (aged 45 +/- 12 yr and BMI 24.6 +/- 4.4 kg/m(2)) during a 19-day trek to Makalu Base Camp. Comparisons were made between three periods of the trek: a 5-day climb below 2500 m (low altitude 1: LA1), an 8-day period between 3500 m and 5200 m (high altitude: HA), and a 4-day descent below 2500 m (low altitude 2: LA2). Body weight was significantly reduced at the end of the trek (p < 0.01). A decrease in total EI was observed at HA (p < 0.05). This was followed by an increase in EI upon return to LA2 (p < 0.001). Neither EI nor macronutrient composition of the diet was associated with the presence of AMS. In conclusion, a decrease in EI was observed in HA, which does not seem to be macronutrient specific.