Dietary protein intake is associated with lean body mass in community-dwelling older adults

Lean body mass (LBM) is important to maintain physical function during aging. We hypothesized that dietary protein intake and leisure-time physical activity are associated with LBM in community-dwelling older adults. To test the hypothesis, participants (n = 237; age, 65-92 years) did 3-day weighed food records and reported physical activity. Body composition was assessed using dual-energy x-ray absorptiometry. Protein intake was 0.98 ± 0.28 and 0.95 ± 0.29 g/kg body weight in male and female participants, respectively. Protein intake (in grams per kilogram of body weight) was associated with LBM (in kilograms); that is, the differences in LBM were 2.3 kg (P < .05) and 2.0 kg (P = .054) between the fourth vs the first and the fourth vs the second quartiles of protein intake, respectively. Only a minor part of this association was explained by increased energy intake, which follows an increased protein intake. Our study shows that dietary protein intake was positively associated with LBM in older adults with a mean protein intake higher than the current recommended daily allowance of 0.8 g/kg per day. Leisure-time physical activity, predominantly consisting of endurance type exercises, was not related to LBM in this group.     

Estimated equilibrated dietary intakes for nine minerals (Na, K, Ca, Mg, P, Fe, Zn, Cu, and Mn) adjusted by mineral balance medians in young Japanese females

The present study sought to determine estimated equilibrated dietary intakes (EEDIs) for nine essential minerals: sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), phosphorus (P), iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn), using data from 17 human mineral balance studies conducted from 1986 to 2007 (subjects=178). Among these studies, two used male subjects, two subjected some or all subjects to sodium restriction, and one study utilized a low protein diet; these subjects were not included in the present analysis. Consequently, data from 13 studies of young female subjects (n=131) consuming a standard diet were selected. Balance distribution medians for six of the minerals (Na, K, Mg, Fe, Zn and Cu) were positive, so the data were adjusted to set the medians of the balances to zero. Medians for the other minerals (Ca, P and Mn) were close to zero and were not adjusted. Intake and balance for each mineral were divided by body weight (BW), lean body mass (LBM), and standard body weight (SBW), which was calculated using height and standard body mass index (BMI=22), and EEDIs were calculated as the intercept of a simple regression equation. When relationships between intake and balance of a mineral were not significant in the regression equation, a significant regression equation comparing intake and balance of another mineral was used to calculate the intercept. Significant simple regression equations were not obtained from any of the three parameters of Na or Zn, or for two of the parameters of P; thus, K, Fe and Ca balances were used to determine the intercepts for Na, Zn and P, respectively. EEDIs for the minerals were: Na (67.9, 89.0, 62.5), K (39.5, 53.5, 37.4), Ca (11.0, 14.4, 10.1), Mg (4.18, 5.51, 3.86), P (18.7, 24.6, 17.3) (mg/kg BW/d, mg/kg LBM/d, mg/kg SBW/d), Fe (180, 237, 165), Zn (168, 241, 166), Cu (30.9, 42.6, 29.7), Mn (55.1, 72.1, 50.7) (μg/kg BW/d, μg/kg LBM/d, μg/kg SBW/d), respectively. These values are nearly identical to the mean dietary intakes.     

Regional,but not total,body composition changes in overweight and obese adults consuming a higher protein,energy-restricted diet are sex specific

Secondary analyses of data from 2 studies were used to assess the effects of protein intake and sex on diet-induced changes in body composition. The primary hypothesis was that the changes of body composition via energy restriction (ie, lean body mass [LBM], fat mass [FM], and bone) would be sex and diet specific. For 12 weeks, 43 male (study 1) and 45 female (study 2) overweight and obese adults consumed an energy-deficit diet (750 kcal/d less than energy needs) containing either 0.8 (normal protein [NP], 21 men and 23 women) or 1.4 g protein?kg⁻¹?d⁻¹ (high protein [HP], 22 men and 22 women). Body composition measurements were performed at preintervention and postintervention. Over time, all research participants lost weight, LBM, and FM. Independent of protein intake, the men lost more LBM in the trunk (−0.9 vs −0.5 kg) and less in the legs (−1.5 vs −1.1 kg) compared with the women (P < .05). Independent of sex, the HP group lost less LBM in the trunk and legs than the NP group. These sex and protein intake responses resulted in the NP men losing the most LBM in the legs and the NP women losing the most LBM in the trunk. Over time, men lost more FM (−5.0 vs −3.9 kg) from the trunk and less from legs (−1.7 vs −2.1 kg) than women (P < .05), which resulted in a greater decrease of the android-to-gynoid fat ratio for the men. Protein intake did not influence these sex-specific responses or have any independent effects on changes in FM. In addition, protein intake did not influence bone mineral density responses over time; bone mineral density was reduced in women, but not in men. These findings indicate that higher protein intake during weight loss promotes the retention of LBM in both the trunk and legs despite the sex-specific changes in these body regions.     

Whole-body protein turnover of a carnivore,Felis silvestris catus

The cat (Felis silvestris catus) has a higher dietary protein requirement than omnivores and herbivores, thought to be due to metabolic inflexibility. An aspect of metabolic flexibility was examined with studies of whole-body protein turnover at two levels of dietary protein energy, moderate protein (MP; 20 %) and high protein (HP; 70 %), in five adult cats in a crossover design. Following a 14 d pre-feed period, a single intravenous dose of [15N]glycine was administered and cumulative excretion of the isotope in urine and faeces determined over 48 h. N flux increased (P<0.005) with dietary protein, being 56 (se 5) mmol N/kg body weight (BW) per d for cats fed the MP diet and 146 (se 8) mmol N/kg BW per d for cats fed the HP diet. Protein synthesis was higher (P<0.05) on the HP diet (75 (se 10) mmol N/kg BW per d; 6.6 (se 1) g protein/kg BW per d) than the MP diet (38 (se 5) mmol N/kg BW per d; 3.4 (se 0.4) g protein/kg BW per d). Protein breakdown was higher (P<0.05) on the HP diet (72 (se 8) mmol N/kg BW per d; 6.3 (se 0.7) g protein/kg BW per d) than the MP diet (44 (se 3) mmol N/kg BW per d; 3.9 (se 0.3) g protein/kg BW per d). Compared with other species the rate of whole-body protein synthesis in the well-nourished cat (9.7 (se 1.3) g protein/kg BW0.75 per d) is at the lower end of the range. These results show that feline protein turnover adapts to dietary protein as has been shown in other species and demonstrates metabolic flexibility. Further work is required to determine exactly why cats have such a high protein requirement.     

Little effect of physical training on body composition and nutritional intake following colorectal surgery--a randomised placebo-controlled trial

OBJECTIVE: Postoperatively patients have a reduction in nutritional intake and body weight. We studied the effect of postoperative physical training on nutritional intake and body composition. METHODS: Patients > or =60 y admitted for elective colorectal surgery were randomised to train muscular strength (group A) or to nonstrengthening exercises (group B) for 3 months. Fat mass (FM) and lean body mass (LBM) were assessed with bioimpedance preoperatively, 7, 30, and 90 days postoperatively. Nutritional intake was registered in a subpopulation. RESULTS: Of 119 included patients, 60 were randomised to group A and 59 to B. The changes in LBM at postoperative day 7 were a mean (s.d.) of 0.4 (2.1) kg in group A compared to -0.7 (2.0) kg in B. The difference between groups of 1.2 (0.5) kg at day 7 was statistically significant (P=0.03). At no other time was observed difference between groups in weight, LBM, or FM. The energy and protein intake rose during postoperative day 1-7 and rose further after discharge. At no time were differences between groups. CONCLUSION: Physical training had little effect on body composition following abdominal surgery. The nutritional intake in well-nourished patients did not increase by training.     

Effects of variation in protein and carbohydrate intake on body mass and composition during energy restriction: a meta-regression 1

BACKGROUND: It is unclear whether low-carbohydrate, high-protein, weight-loss diets benefit body mass and composition beyond energy restriction alone. OBJECTIVE: The objective was to use meta-regression to determine the effects of variations in protein and carbohydrate intakes on body mass and composition during energy restriction. DESIGN: English-language studies with a dietary intervention of > or =4200 kJ/d (1000 kcal/d), with a duration of > or =4 wk, and conducted in subjects aged > or =19 y were considered eligible for inclusion. A self-reported intake in conjunction with a biological marker of macronutrient intake was required as a minimum level of dietary control. A total of 87 studies comprising 165 intervention groups met the inclusion criteria. RESULTS: After control for energy intake, diets consisting of < or =35-41.4% energy from carbohydrate were associated with a 1.74 kg greater loss of body mass, a 0.69 kg greater loss of fat-free mass, a 1.29% greater loss in percentage body fat, and a 2.05 kg greater loss of fat mass than were diets with a higher percentage of energy from carbohydrate. In studies that were conducted for >12 wk, these differences increased to 6.56 kg, 1.74 kg, 3.55%, and 5.57 kg, respectively. Protein intakes of >1.05 g/kg were associated with 0.60 kg additional fat-free mass retention compared with diets with protein intakes < or =1.05 g/kg. In studies conducted for >12 wk, this difference increased to 1.21 kg. No significant effects of protein intake on loss of either body mass or fat mass were observed. CONCLUSION: Low-carbohydrate, high-protein diets favorably affect body mass and composition independent of energy intake, which in part supports the proposed metabolic advantage of these diets.     

儿童最大吸氧量与体格发育关系的研究

本文报告了４３６名１０－１９岁男女儿童少年最大吸氧量与休格发育的关系。相关分析可见，ＶＯ２ｍａｘ，ＶＯ２ｍａｘ／身高及ＶＯ２ｍａｘ／最大心率与身高，体重及瘦体重等体格发育变量有高度正相关；ＶＯ２ｍａｘ／体重与各体格变量，男童呈较低的正相关，妇童为较低的负相关；ＶＯ２ｍａｘ／ＬＢＭ与各体格变量，男女童均无相关。按身高，体重及ＬＢＭ分组，将男女儿童分别为发育较好（第１）组及较差（第２）组，比较两组ＶＯ     

Dynapenic Abdominal Obesity Increases Mortality Risk Among English and Brazilian Older Adults: A 10-Year Follow-Up of the ELSA and SABE Studies

Background/Objective

There is little epidemiological evidence demonstrating that dynapenic abdominal obesity has higher mortality risk than dynapenia and abdominal obesity alone. Our main aim was to investigate whether dynapenia combined with abdominal obesity increases mortality risk among English and Brazilian older adults over ten-year follow-up.

Design

Cohort study.

Setting

United Kingdom and Brazil.

Participants

Data came from 4,683 individuals from the English Longitudinal Study of Ageing (ELSA) and 1,490 from the Brazilian Health, Well-being and Aging study (SABE), hence the final sample of this study was 6,173 older adults.

Measurements

The study population was categorized into the following groups: nondynapenic/ non-abdominal obese, abdominal obese, dynapenic, and dynapenic abdominal obese according to their handgrip strength (< 26 kg for men and < 16 kg for women) and waist circumference (> 102 cm for men and > 88 cm for women). The outcome was all-cause mortality over a ten-year follow-up. Adjusted hazard ratios by sociodemographic, behavioural and clinical characteristics were estimated using Cox proportional hazards models. Results: The fully adjusted model showed that dynapenic abdominal obesity has a higher mortality risk among the groups. The hazard ratios (HR) were 1.37 for dynapenic abdominal obesity (95% CI = 1.12–1.68), 1.15 for abdominal obesity (95% CI = 0.98–1.35), and 1.23 for dynapenia (95% CI = 1.04–1.45).

Conclusions

Dynapenia is an important risk factor for mortality but dynapenic abdominal obesity has the highest mortality risk among English and Brazilian older adults.

     

Effect of a high-protein energy-restricted diet combined with resistance training on metabolic profile in older individuals with metabolic impairments

Adequate protein intake and resistance training are effective strategies to maintain muscle mass, but the effect of their combination on metabolic profile during weight loss remains to be determined in older adults. The main objective of this study was to determine the effect of a 16-week high-protein caloric restriction combined with resistance training on chronic disease risk factors in obese older individuals with metabolic impairments. A total of 26 overweight adults aged between 60 and 75 years (BMI 32.4 ± 3.9 kg/m²) with at least 2 factors of the metabolic syndrome participated in this study and were randomized into two groups: 1) high-protein caloric restriction (HP; n= 12) and 2) high-protein caloric restriction combined with dynamic-resistance training (HP+RT; n=14). Caloric intake was reduced by 500 kcal/d in all participants and protein intake equated 25-30% of total calories (~1.4 g/kg/d). Exercise training consisted of 3 session/week of resistance training on pulley machines. Outcome measures included total and trunk fat mass (FM), total and appendicular lean body mass (LBM), fasting glucose level, lipid profile and blood pressure. Our results showed that total and trunk FM (all p<0.0001) as well as fasting glucose (p<0.0001), triglycerides (p=0.002) and total cholesterol (p=0.03) levels decreased similarly in both groups. However, total (p=0.04) and appendicular (p=0.02) LBM decreased in the HP group only. Our data show that high-protein energy restriction improves health profile of obese elderly at high risk of chronic disease but needs to be combined with resistance training to maintain LBM.     

Effects of protein-rich supplementation and nandrolone in lean elderly women with femoral neck fractures

AIM: To evaluate the effects of a protein-rich liquid supplementation, alone or in combination with the anabolic steroid nandrolone decanoate, on body composition, activities of daily living (ADL) status and the health-related quality of life (HRQoL) after a femoral neck fracture. METHODS: Sixty women, aged 83 +/- 5 years (mean +/- SD), BMI < 24 kg/m2 (20.4 +/- 2 kg/m2 ) and capable of co-operating, with a femoral neck fracture treated with internal fixation, were randomised to open treatment during 6 months with a protein-rich liquid formula alone (PR, Fortimel, 200 ml/day, 20 g protein/day) or in combination with nandrolone decanoate (PR/N, Deca-Durabol 25 mg i.m./3 weeks) or to a control group (C). The patients were re-examined after 6 and 12 months regarding body weight (BW), lean body mass (LBM, DXA), ADL status according to Katz, HRQoL according to EQ 5-D and fracture healing. RESULTS: LBM decreased in the C (-1.2 +/- 2 kg) and PR groups (-1.2 +/- 1 kg) but remained the same in the PR/N group (0.3 +/- 1 kg) (P < 0.05 between groups). ADL remained at a high level in the two intervention groups but declined significantly in the C group (P < 0.005 between groups). The decline in HRQoL was least pronounced in the PR/N group at 6 months (P < 0.05 between groups). Patients with fracture healing complications lost more BW (P < 0.05) and LBM (P < 0.01) than patients with uneventful fracture healing. CONCLUSION: Protein-rich liquid supplementation in combination with nandrolone given for 6 months to lean elderly women after a femoral neck fracture may positively affect LBM, ADL and HRQoL.     

Effects of Milk Protein in Resistance Training-Induced Lean Mass Gains for Older Adults Aged ≥ 60 y: A Systematic Review and Meta-Analysis

This review evaluated the effects of milk-based protein supplementation on resistance training (RT)-induced gains in lean body mass or fat free mass (LBM/FFM) and muscle strength for older adults. A systematic search of PubMed, Scopus and EBSCOhost/SPORTDiscus was conducted. Eligibility criteria: Randomized controlled trials comparing all types of milk-based protein supplements with control supplements for the training older adults at mean age ≥ 60 y. Twenty studies were included in the qualitative synthesis, whilst seventeen studies were included in the quantitative synthesis. A dose of 10–15 g of milk protein supplementation was sufficient to augment RT-induced LBM/FFM. Intriguingly, four out of five studies show negative effect of whey protein supplementation at the same dose range (or even higher) compared with control supplementation (−0.49 kg, 95% CI: −0.69, −0.29, I² = 14%, Z = 4.82, p < 0.001). For milk-based protein supplementation, RT-induced improvements in muscle strength were observed only when the protein doses ≥22 g (+0.66 kg, 95% CI: 0.07, 1.25, I² = 0%, Z = 2.18, p = 0.03). Conclusion: Milk protein is superior to whey protein in enhancing RT-induced LBM/FFM gains for older adults. Optimal daily protein intake can dilute the protein supplementation effect.     

Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study

BACKGROUND: The current study was designed to examine whether a combination of three nutrients, consisting of beta-hydroxy-beta-methylbutyrate (HMB), a metabolite of leucine, L-glutamine (Gln) and L-arginine (Arg), each of which has been previously shown to slow muscle proteolysis, could synergistically alter the course of muscle wasting in patients with established acquired immunodeficiency syndrome (AIDS). METHODS: Sixty-eight human immunodeficiency virus (HIV)-infected patients with a documented weight loss of at least 5% in the previous 3 months were recruited from the HIV clinic at Nassau County Medical Center. The subjects were randomly assigned in a double-blind fashion to receive either placebo containing maltodextrin or the nutrient mixture (HMB/Arg/Gln) containing 3 g HMB, 14 g L-glutamine, and 14 g L-arginine given in two divided doses daily for 8 weeks. Body weights (BW) were recorded weekly and lean body mass (LBM) and fat mass (FM) were measured by air displacement plethysmography and by a single computerized tomography (CT) slice through the thigh at 0, 4, and 8 weeks. RESULTS: Forty-three subjects completed the 8-week protocol, (placebo, n = 21; HMB/Arg/Gln, n = 22). At 8 weeks, the subjects consuming the HMB/Arg/Gln mixture gained 3.0 +/- 0.5 kg of BW while those supplemented with the placebo gained 0.37 +/- 0.84 kg (p = .009). The BW gain in the HMB/Arg/Gln-treated subjects was predominantly LBM (2.55 +/- 0.75 kg) compared with the placebo-supplemented subjects who lost lean mass (-0.70 +/- 0.69 kg, p = .003). No significant change in FM gain was observed (0.43 +/- 0.83 kg for the group receiving HMB/Arg/Gln and 1.07 +/- 0.64 kg for the group receiving the placebo, p > .20). Similar percentage changes in muscle mass and fat mass were observed with CT scans. Immune status was also improved as evident by an increase in CD3 and CD8 cells and a decrease in the HIV viral load with HMB/Arg/Gln supplementation. CONCLUSIONS: The data indicate that the HMB/Arg/Gln mixture can markedly alter the course of lean tissue loss in patients with AIDS-associated wasting.     

Protein and energy requirements of fingerling channel catfish for maintenance and maximum growth

In two separate experiments, purified diets containing 25% crude protein and 2.85 kcal/g and 35% crude protein and 3.99 kcal/g were fed at incremental rates [0-5% of body weight (BW)/d] to fingerling channel catfish (Ictalurus punctatus) in aquaria for 8 wk. Linear (r2 = 0.95) increases in growth rate were observed in each experiment with increases in feeding rate up to 8.75 g protein/(kg BW X d) and 99.75 kcal energy/(kg BW X d). Regressing growth rate back to zero resulted in maintenance requirement values of 1.32 g protein/(kg BW X d) and 15.06 kcal energy/(kg BW X d) for experiment 1 and 1.32 g protein/(kg BW X d) and 15.08 kcal energy/(kg BW X d) for experiment 2. Net gains in body protein and energy also increased linearly (r2 = 0.93) with increasing feeding rates up to 8.75 g protein/(kg BW X d) and 99.75 kcal energy/(kg BW X d) in both experiments. Regression equations from these data predicted 1.07 g protein/(kg BW X d) and 17.00 kcal energy/(kg BW X d) in experiment 1 and 1.00 g protein/(kg BW X d) and 17.33 kcal energy/(kg BW X d) in experiment 2 was required to maintain a constant amount of protein and energy in catfish tissue. These requirement values for maintenance and maximum gain agree closely with those predicted from growth data.     

Long-term effects of a high-protein weight-loss diet

BACKGROUND: Evidence that high-protein diets are an effective strategy for the maintenance of long-term weight loss is limited. OBJECTIVE: The objective was to determine the efficacy of a higher protein intake on the maintenance of weight loss after 64 wk of follow-up. DESIGN: Seventy-nine healthy women with a mean (+/-SD) age of 49+/-9 y and a body mass index (in kg/m2) of 32.8+/-3.5 completed an intensive 12-wk weight-loss program and 52 wk of follow-up to compare the effects on weight-loss maintenance of a high-protein (HP) diet (34% of energy) or a high-carbohydrate (HC) diet (64% of energy). RESULTS: Mean (+/-SD) weight loss was not significantly different between groups: (HP: 4.6+/-5.5 kg; HC: 4.4+/-6.1 kg). Protein intake (g) from dietary records at 64 wk was directly related to weight loss (P<0.0001), accounting for 15% of the variance. Protein intake as a percentage of energy was also related to weight change (P=0.003), accounting for 10% of the variance. In the upper tertile (88 g protein/d), weight loss was 6.5+/-7.5 and 3.4+/-4.4 kg (P=0.03) in the 2 lower tertiles, respectively. This difference did not translate to a difference in central fat loss between groups. Lipids, glucose, insulin, C-reactive protein, and homocysteine all improved with weight loss and were not significantly different between groups. HDL cholesterol rose by 20%. Higher serum vitamin B-12 was observed in the HP group, and folate concentrations were not significantly different between groups. CONCLUSIONS: A reported higher protein intake appears to confer some weight-loss benefit. Cardiovascular disease risk factors, biomarkers of disease, and serum vitamins and minerals improved with no differences between groups.     

The effect of dietary protein content and feeding level on the rate of protein deposition and energy utilization in growing Iberian pigs from 15 to 50 kg body weight

The effects of dietary protein content and feeding level on the utilization of metabolizable energy (ME) and on the rates of gain, protein and fat deposition have been studied in seventy-two Iberian pigs growing from 15 to 50 kg body weight (BW) by means of comparative slaughter experiments. The animals were fed on six diets providing 223, 192, 175, 156, 129 and 101 g crude ideal protein ( CP)/kg DM and 14.64, 14.14, 14.37, 14.80, 15.36 and 15.53 MJ ME/kg DM respectively. Each diet was offered at three levels of feeding: 0.60, 0.80 and 0.95xad libitum intake. Protein deposition (PD) increased significantly (P<0.01) with each decrease in dietary CP content and reached a maximum value (74.0 g) when the diet providing 129 g CP/kg DM (6.86 g digestible ideal protein/MJ ME) was offered at the highest feeding level. This feeding regimen resulted in average values for live-weight gain and retained energy (RE) of 559 g/d and 10.9 MJ/d respectively. RE increased significantly (P<0.001) from 480 to 626 kJ/kg BW0.75 with each decrease in dietary CP content from 192 to 129 g/kg DM. Raising the level of feed intake led to significant linear increases in PD and RE irrespective of the diet fed (P<0.001). When diets approaching an adequate supply of CP were given, the net efficiency of use of ME for growth (kw) and the maintenance energy requirements were 58.2 % and 422 kJ/kg BW0.75 per d respectively.     

Effect of Interaction Between Dynapenic Component of the European Working Group on Sarcopenia in Older People Sarcopenia Criteria and Obesity on Activities of Daily Living in the Elderly

ObjectivesTo examine the effects of interaction between dynapenic component of the European Working Group on Sarcopenia in Older People (EWGSOP) sarcopenia and obesity (dynapenia × obesity) on activities of daily living (ADL) in older participants.DesignCross-sectional analysis of the Validity and Reliability of Korean Frailty Index and the Validity and Reliability of the Kaigo-Yobo Checklist in Korean Elderly studies.SettingSix welfare facilities operated by government in South Korea.ParticipantsFour hundred eighty-seven community-dwelling individuals (157 males, 330 females) >65 years of age.MeasurementDynapenic component of the EWGSOP sarcopenia was defined as usual gait speed <0.8 m/s or grip strength lower than cut-off value (male <25.3 kg, female <12.0 kg). Obesity was defined as body mass index ≥27.5 kg/m². ADL were assessed using the Barthel index.ResultsThere were 14 obese with dynapenic component cases (2 males, 12 females) of the 487 participants. Interaction of dynapenia and obesity was significant on multivariate generalized linear model analysis (P = .015).ConclusionsDynapenic component of the EWGSOP sarcopenia and obesity in the elderly is associated with multiplicative interactions rather than additive interactions in ADL.     

Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes

When weight loss (WL) is necessary, athletes are advised to accomplish it gradually, at a rate of 0.5-1 kg/wk. However, it is possible that losing 0.5 kg/wk is better than 1 kg/wk in terms of preserving lean body mass (LBM) and performance. The aim of this study was to compare changes in body composition, strength, and power during a weekly body-weight (BW) loss of 0.7% slow reduction (SR) vs. 1.4% fast reduction (FR). We hypothesized that the faster WL regimen would result in more detrimental effects on both LBM and strength-related performance. Twenty-four athletes were randomized to SR (n = 13, 24 ± 3 yr, 71.9 ± 12.7 kg) or FR (n = 11, 22 ± 5 yr, 74.8 ± 11.7 kg). They followed energy-restricted diets promoting the predetermined weekly WL. All athletes included 4 resistance-training sessions/wk in their usual training regimen. The mean times spent in intervention for SR and FR were 8.5 ± 2.2 and 5.3 ± 0.9 wk, respectively (p < .001). BW, body composition (DEXA), 1-repetition-maximum (1RM) tests, 40-m sprint, and countermovement jump were measured before and after intervention. Energy intake was reduced by 19% ± 2% and 30% ± 4% in SR and FR, respectively (p = .003). BW and fat mass decreased in both SR and FR by 5.6% ± 0.8% and 5.5% ± 0.7% (0.7% ± 0.8% vs. 1.0% ± 0.4%/wk) and 31% ± 3% and 21 ± 4%, respectively. LBM increased in SR by 2.1% ± 0.4% (p < .001), whereas it was unchanged in FR (-0.2% ± 0.7%), with significant differences between groups (p < .01). In conclusion, data from this study suggest that athletes who want to gain LBM and increase 1RM strength during a WL period combined with strength training should aim for a weekly BW loss of 0.7%.     

Total body potassium, fat and water during total parenteral nutrition in Crohn's disease

The body composition was studied by measurement of body weight (BW) and total body potassium (TBK), fat and water in 13 patients with Crohn's disease (CD), who were given altogether 18 courses of total parenteral nutrition (TPN) with nil by mouth each lasting at least 3 weeks. At the start of TPN, one group of steroid-free patients displayed intracellular potassium depletion, as reflected by the ratio TBK/lean body mass (LBM) (group 1). Another group of steroid-free patients showed no depletion of intracellular potassium (group 2). The patients given prednisolone all showed intracellular potassium depletion and were assigned to a separate group (group 3). During the initial 19-44 days of TPN, TBK, LBM and BW increased in group 1. All patients with intracellular potassium depletion (groups 1 + 3) showed an increase in TBK and TBK/LBM during the initial 19-51 days of TPN. For steroid-free patients (groups 1 + 2) there were linear relationships between the rate of energy supply per kg LBM and the 24 h change in BW during the third and fourth weeks of TPN (r = 0.79) and between the 24 h change inBW and LBM during the first 19-44 days of TPN (r = 0.59). A steady state in BW was found on administering 53 kcal/kg LBM/24 h. It is concluded that CD patients with intracellular potassium depletion are likely to be improved in terms of TBK and TBK/LBM by at least 3 weeks of TPN as given in the present study. Steroid-free CD patients with intracellular potassium depletion are, moreover, likely to show an improvement in LBM by at least 3 weeks of TPN, and an increase in their BW during the initial 3-6 weeks of TPN will probably reflect an increase in LBM. The pre-TPN TBK/LBM ratio may be a predictor of the repletion rate of the LBM compartment during TPN of steroid-free wasted CD patients.     

Does a Higher Protein Diet Promote Satiety and Weight Loss Independent of Carbohydrate Content? An 8-Week Low-Energy Diet (LED) Intervention

Both higher protein (HP) and lower carbohydrate (LC) diets may promote satiety and enhance body weight (BW) loss. This study investigated whether HP can promote these outcomes independent of carbohydrate (CHO) content. 121 women with obesity (BW: 95.1 ± 13.0 kg, BMI: 35.4 ± 3.9 kg/m²) were randomised to either HP (1.2 g/kg BW) or normal protein (NP, 0.8 g/kg BW) diets, in combination with either LC (28 en%) or normal CHO (NC, 40 en%) diets. A low-energy diet partial diet replacement (LED_pdr) regime was used for 8 weeks, where participants consumed fixed-energy meal replacements plus one ad libitum meal daily. Four-day dietary records showed that daily energy intake (EI) was similar between groups (p = 0.744), but the difference in protein and CHO between groups was lower than expected. Following multiple imputation (completion rate 77%), decrease in mean BW, fat mass (FM) and fat-free mass (FFM) at Week 8 in all was 7.5 ± 0.7 kg (p < 0.001), 5.7 ± 0.5 kg (p < 0.001), and 1.4 ± 0.7 kg (p = 0.054) respectively, but with no significant difference between diet groups. LC (CHO×Week, p < 0.05), but not HP, significantly promoted postprandial satiety during a preload challenge. Improvements in blood biomarkers were unrelated to LED_pdr macronutrient composition. In conclusion, HP did not promote satiety and BW loss compared to NP LED_pdr, irrespective of CHO content.     

Pre- and post-season dietary intake, body composition, and performance indices of NCAA division I female soccer players

Little published data describe the dietary and physiological profiles of intercollegiate female soccer players; therefore, the purpose of this investigation was to report baseline dietary data, anthropometrics, and performance indices of soccer women during rigorous pre-season training (2 sessions/day) and then during the post-competitive season. Members of a NCAA Division I women's soccer squad completed 3-day diet records, anthropometrics, and physical tests, including VO2peak. Average body mass was 62 kg with 16% body fat, and no significant pre to post differences were observed. Total energy, carbohydrate (CHO), protein, and fat intakes were significantly greater during the pre-season. Pre-season energy intake met the DRI for females with an "active" lifestyle (37 kcal/kg). While CHO intake failed to meet minimum recommendations to promote glycogen repletion (7-10 g/kg), protein and fat intakes were above minimum recommendations. Pre- and post-season intakes of several micronutrients were marginal (<75% of the DRI) including vitamin E, folate, copper, and magnesium. VO2peak significantly improved from pre- to post-season (42 and 50 ml/kg/min). In this study female soccer players appeared to meet caloric needs during periods of training but failed to meet minimum CHO and micronutrient recommendations. Foods higher in protein and fat displaced more CHO-rich and nutrient-dense foods within athletes' energy requirements and satiety limits.