Prospective study of nut consumption, long-term weight change, and obesity risk in women

Prospective study of nut consumption, long-term weight change, and obesity risk in women

from American Journal of Clinical Nutrition current issue by Bes-Rastrollo, M., Wedick, N. M, Martinez-Gonzalez, M. A., Li, T. Y, Sampson, L., Hu, F. B

Background: Data concerning the long-term association between nut consumption and weight change in a free-living population are sparse.

Objective: The objective was to determine the relation between nut consumption and long-term weight change.

Design: The participants were 51,188 women in the Nurses' Health Study II aged 20–45 y, who had no cardiovascular disease, diabetes, or cancer. We prospectively evaluated the dietary intake of nuts and subsequent weight changes from 1991 to 1999.

Results: Women who reported eating nuts ?2 times/wk had slightly less mean (± SE) weight gain (5.04 ± 0.12 kg) than did women who rarely ate nuts (5.55 ± 0.04 kg) (P for trend < 0.001). For the same comparison, when total nut consumption was subdivided into peanuts and tree nuts, the results were similar (ie, less weight gain in women eating either peanuts or tree nuts ?2 times/wk). The results were similar in normal-weight, overweight, and obese participants. In multivariate analyses in which lifestyle and other dietary factors were controlled for, we found that greater nut consumption (?2 times/wk compared with never/almost never) was associated with a slightly lower risk of obesity (hazard ratio: 0.77; 95% CI: 0.57, 1.02; P for trend = 0.003).

Conclusions: Higher nut consumption was not associated with greater body weight gain during 8 y of follow-up in healthy middle-aged women. Instead, it was associated with a slightly lower risk of weight gain and obesity. The results of this study suggest that incorporating nuts into diets does not lead to greater weight gain and may help weight control.

Appl Physiol Nutr Metab. 2009 Jun;34(3):403-10.Related Articles, Links Physiologic and molecular bases of muscle hypertrophy and atrophy: impact of resistance exercise on human skeletal muscle (protein and exercise dose effects). Phillips SM. Exercis

Physiologic and molecular bases of muscle hypertrophy and atrophy: impact of resistance exercise on human skeletal muscle (protein and exercise dose effects).

Phillips SM.

Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada (e-mail: phillis@mcmaster.ca).

Normally, skeletal muscle mass is unchanged, beyond periods of growth, but it begins to decline in the fourth or fifth decade of life. The mass of skeletal muscle is maintained by ingestion of protein-containing meals. With feeding, muscle protein synthesis (MPS) is stimulated and a small suppression of muscle protein breakdown (MPB) occurs, such that protein balance becomes positive (MPS > MPB). As the postprandial period subsides and a transition toward fasting occurs, the balance of muscle protein turnover becomes negative again (MPB > MPS). Thus, during maintenance of skeletal muscle mass, the long-term net result is that MPS is balanced by MPB. Acutely, however, it is of interest to determine what regulates feeding-induced increases in MPS, since it appears that, in a number of scenarios (for example aging, disuse, and wasting diseases), a suppression of MPS in response to feeding is a common finding. In fact, recent findings point to the fact that loss of skeletal muscle mass with disuse and aging is due not chronic changes in MPS or MPB, but to a blunted feeding-induced rise in MPS. Resistance exercise is a potent stimulator of MPS and appears to synergistically enhance the gains stimulated by feeding. As such, resistance exercise is an important countermeasure to disuse atrophy and to age-related declines in skeletal muscle mass. What is less well understood is how the intensity and volume of the resistance exercise stimulus is sufficient to result in rises in MPS. Recent advances in this area are discussed here, with a focus on human in vivo data.

Almonds have a neutral effect on serum lipid profiles: a meta-analysis of randomized trials.

Almonds have a neutral effect on serum lipid profiles: a meta-analysis of randomized trials.

Phung OJ, Makanji SS, White CM, Coleman CI.

University of Connecticut, Hartford Hospital Evidence-Based Practice Center, Hartford, CT 06102-5037, USA.

Almond consumption may be associated with improvements in serum lipid profiles. The aim was to evaluate the influence of almonds on lipid parameters to help define the role of almonds as a lipid modulator. MEDLINE, EMBASE, Cochrane CENTRAL, and the Natural Medicines Comprehensive Database were searched through July 2008, with no language restrictions, for randomized controlled trials of almonds in human patients that reported efficacy data on at least one of the following endpoints: total, low-density lipoprotein (LDL), or high-density lipoprotein (HDL) cholesterol, triglycerides, or the LDL:HDL ratio. A manual search of references from primary or review articles was performed to identify additional relevant trials. Five randomized, controlled trials (totaling 142 participants) met all inclusion criteria. Upon meta-analysis, almond consumption ranging from 25 to 168 g/day significantly lowered total cholesterol [weighted mean difference -6.95 mg/dL (95% confidence interval [CI] -13.12 to -0.772) (-0.18 mmol/L [95% CI -0.34 to -0.02])] and showed a strong trend toward reducing LDL cholesterol [weighted mean difference -5.79 mg/dL (95% CI -11.2 to 0.00) (-0.15 mmol/L [95% CI -0.29 to 0.00])]. No significant effect on HDL cholesterol, triglycerides, or LDL:HDL ratio was found. No statistical heterogeneity was observed for any analysis (I2=0% for all). Review of funnel plots and the Egger's weighted regression statistic P values suggested a low likelihood of publication bias in all analyses (P>0.25 for all). Almond consumption may decrease total cholesterol and does not significantly affect LDL or HDL cholesterol, triglycerides, or the LDL:HDL ratio. The current body of randomized trials does not support the ingestion of almonds solely for their lipid modifying effects. Both the lipid modulating effects and the safety/tolerability of almonds should be further investigated through the conduction of larger randomized, double-blinded trials of longer duration. Such studies might focus specifically on whether the efficacy of almonds as a lipid modulator varies by dose or comorbidity.

Calcium absorption from fortified ice cream formulations compared with calcium absorption from milk.

Calcium absorption from fortified ice cream formulations compared with calcium absorption from milk.

van der Hee RM, Miret S, Slettenaar M, Duchateau GS, Rietveld AG, Wilkinson JE, Quail PJ, Berry MJ, Dainty JR, Teucher B, Fairweather-Tait SJ.

Unilever Food and Health Research Institute, PO Box 114, 3130 AC Vlaardingen, The Netherlands. Regine-van-der.Hee@unilever.com

OBJECTIVE: Optimal bone mass in early adulthood is achieved through appropriate diet and lifestyle, thereby protecting against osteoporosis and risk of bone fracture in later life. Calcium and vitamin D are essential to build adequate bones, but calcium intakes of many population groups do not meet dietary reference values. In addition, changes in dietary patterns are exacerbating the problem, thereby emphasizing the important role of calcium-rich food products. We have designed a calcium-fortified ice cream formulation that is lower in fat than regular ice cream and could provide a useful source of additional dietary calcium. Calcium absorption from two different ice cream formulations was determined in young adults and compared with milk. SUBJECTS/SETTING: Sixteen healthy volunteers (25 to 45 years of age), recruited from the general public of The Netherlands, participated in a randomized, reference-controlled, double-blind cross-over study in which two test products and milk were consumed with a light standard breakfast on three separate occasions: a standard portion of ice cream (60 g) fortified with milk minerals and containing a low level (3%) of butter fat, ice cream (60 g) fortified with milk minerals and containing a typical level (9%) of coconut oil, and reduced-fat milk (1.7% milk fat) (200 mL). Calcium absorption was measured by the dual-label stable isotope technique. STATISTICAL ANALYSIS: Effects on calcium absorption were evaluated by analysis of variance. RESULTS: Fractional absorption of calcium from the 3% butterfat ice cream, 9% coconut oil ice cream, and milk was 26%+/-8%, 28%+/-5%, and 31%+/-9%, respectively, and did not differ significantly (P=0.159). CONCLUSIONS: Results indicate that calcium bioavailability in the two calcium-fortified ice cream formulations used in this study is as high as milk, indicating that ice cream may be a good vehicle for delivery of calcium.

Effects of a popular exercise and weight loss program on weight loss, body composition, energy expenditure and health in obese women

Effects of a popular exercise and weight loss program on weight loss, body composition, energy expenditure and health in obese women

from Nutrition & Metabolism - Latest articles 

by Chad Kerksick, Ashli Thomas, Bill Campbell, Lem Taylor, Colin Wilborn, Brandon Marcello, Mike Roberts, Emily Pfau, Megan Grimstvedt, Jasmine Opusunju, Teresa Magrans-Courtney, Chris Rasmussen, Ron Wilson and Richard Kreider

Objective

To determine the safety and efficacy of altering the ratio of carbohydrate and protein in low-energy diets in conjunction with a popular exercise program in obese women. Design: 

Matched, prospective clinical intervention study to assess efficacy of varying ratios of carbohydrate and protein intake in conjunction with a regular exercise program. Participants: 

One-hundred sixty one sedentary, obese, pre-menopausal women (38.5+/-8.5 yrs, 164.2+/-6.7 cm, 94.2+/-18.8 kg, 34.9+/-6.4 kg * m-2, 43.8+/-4.2 %) participated in this study. Participants were weight stable and not participating in additional weight loss programs. All participants were medically cleared for disease and were excluded if they were taking any form of dietary supplementation to facilitate weight loss and/or any were currently being treated with other prescription medications. Methods: 

Participants were assigned to either a no exercise + no diet control (CON), a no diet + exercise group (ND), or one of four diet + exercise groups (presented as kcals; % carbohydrate: protein: fat): 1) a high energy, high carbohydrate (CHO), low protein diet (HED) [2,600; 55:15:30 %], 2) a very low carbohydrate, high protein diet (VLCHP) [1,200 kcals; 63:7:30 %], 3) a low carbohydrate, moderate protein diet (LCMP) [1,200 kcals; 50:20:30 %] and 4) a high carbohydrate, low protein diet (HCLP) [1,200 kcals; 55:15:30 %]. Participants in exercise groups (all but CON) performed a pneumatic resistance, circuit training program under supervision three times per week. 

Measurements: 

At 0, 2, 10 and 14 weeks, anthropometric, body composition, resting energy expenditure (REE), fasting blood samples, and muscular fitness assessments were completed. 

Results: 

All groups except CON experienced significant reductions (P<0.05 - 0.001) in waist circumference over 14 weeks. VLCHP, LCHP and LPHC participants experienced similar but significant (P<0.05 - 0.001) reductions in body mass when compared to other groups. Delta responses indicated that fat loss after 14 weeks was significantly greatest in VLCHP (95% CI: -5.2, -3.2 kg), LCMP (-4.0, -1.9 kg) and HCLP (-3.8, -2.1 kg) when compared to other groups. Subsequent reductions in % body fat were significantly greater in VLCHP, LCMP and HCLP participants. Initial dieting decreased (P<0.05) relative REE similarly in all groups. All exercise groups significantly (P<0.05) improved in muscular fitness, but these improvements were not different among groups. Favorable but non-significant mean changes occurred in lipid panels, glucose and HOMA-IR. Leptin levels decreased (P<0.05) in all groups, except for CON, after two weeks of dieting and remained lower throughout the 14 week program. Exercise participation resulted in significant improvements in quality of life and body image. 

Conclusions: 

Exercise alone (ND) appears to have minimal impact on measured outcomes with positive outcomes apparent when exercise is combined with a hypoenergetic diet. Greater improvements in waist circumference and body composition occurred when carbohydrate is replaced in the diet with protein. Weight loss in all diet groups (VLCHP, LCMP and HCLP) was primarily fat and stimulated improvements in markers of cardiovascular disease risk, body composition, energy expenditure and psychosocial parameters.

Minimal Resistance Training Improves Daily Energy Expenditure and Fat Oxidation.

Minimal Resistance Training Improves Daily Energy Expenditure and Fat Oxidation.

Kirk EP, Donnelly JE, Smith BK, Honas J, Lecheminant JD, Bailey BW, Jacobsen DJ, Washburn RA.


Long-term resistance training (RT) may result in a chronic increase in 24-h energy expenditure (EE) and fat oxidation to a level sufficient to assist in maintaining energy balance and preventing weight gain. However, the impact of a minimal RT program on these parameters in an overweight college-aged population, a group at high risk for developing obesity, is unknown. PURPOSE:: We aimed to evaluate the effect of 6 months of supervised minimal RT in previously sedentary, overweight (mean +/- SEM, BMI = 27.7 +/- 0.5 kg.m) young adults (21.0 +/- 0.5 yr) on 24-h EE, resting metabolic rate (RMR), sleep metabolic rate (SMR), and substrate oxidation using whole-room indirect calorimetry 72 h after the last RT session. METHODS:: Participants were randomized to RT (one set, 3 d.wk, three to six repetition maximums, nine exercises; N = 22) or control (C, N = 17) groups and completed all assessments at baseline and at 6 months. RESULTS:: There was a significant (P < 0.05) increase in 24-h EE in the RT (527 +/- 220 kJ.d) and C (270 +/- 168 kJ.d) groups; however, the difference between groups was not significant (P = 0.30). Twenty-four hours of fat oxidation (g.d) was not altered after RT; however, reductions in RT assessed during both rest (P < 0.05) and sleep (P < 0.05) suggested increased fat oxidation in RT compared with C during these periods. SMR (8.4 +/- 8.6%) and RMR (7.4 +/- 8.7%) increased significantly in RT (P < 0.001) but not in C, resulting in significant (P < 0.001) between-group differences for SMR with a trend for significant (P = 0.07) between-group differences for RMR. CONCLUSION:: A minimal RT program that required little time to complete (11min per session) resulted in a chronic increase in energy expenditure. This adaptation in energy expenditure may have a favorable impact on energy balance and fat oxidation sufficient to assist with the prevention of obesity in sedentary, overweight young adults, a group at high risk for developing obesity.