News in Brief February 10th, 2014
Amélioration de la fonction érectile après une perte de poids chez des hommes obèses : l’essai contrôlé randomisé SHED-IT. (Improvement in erectile function following weight loss in obese men: the SHED-IT randomized controlled trial). Collins CE, Jensen ME, Young MD, Callister R, Plotnikoff RC, Morgan PJ. Obes Res Clin Pract. 2013 Dec;7(6):e450-4.
Weight gain is known to affect men’s sexual performances. The authors of this study assessed the improvement in the erectile scores of obese men who had lost weight by dieting and taking physical exercise, as recommended. After a 6-month follow-up period, the participants had lost between 3.7 and 4.7kg and their mean erectile scores on the IIEF-5 questionnaire had improved by 1.4 points. The possibility of improving their sexual performances might therefore motivate overweight men to invest in losing weight.
Diabète et cancer : deux maladies avec un facteur de risque commun, l’obésité. (Diabetes and cancer: two diseases with obesity as a common risk factor.) Garg SK, Maurer H, Reed K, Selagamsetty R. Diabetes Obes Metab. 2013 May 13.
Several epidemiological studies have shown that diabetic subjects run a greater risk of developing some kinds of cancer (breast, colorectal, endometrial, stomach, liver, kidney and pancreatic cancer), which tend to be associated with high mortality rates. It still remains to be determined, however, whether the underlying mechanisms involve inflammatory processes, hyperinsulinemia or hyperglycemia, for example. Some common risk factors have been observed, however, including obesity. Abdominal obesity in particulier may contribute to the development of diabetes and cancer by promoting a pro-inflammatory context, insulin resistance and the circulation of free fatty acids. Some medicinal treatments for diabetes may also favour the development of cancer. The main strategies recommended by the authors consist in improving patients’ lifestyle (by inciting them to give up smoking and lose weight), treating the tumours to make them less aggressive, managing complications and optimising the anti-diabetic treatment.
Régime ou exercice, ou les deux, pour perdre du poids après une grossesse. (Diet or exercise, or both, for weight reduction in women after childbirth. Amorim Adegboye AR, Linne YM. Cochrane Database Syst Rev. 2013 Jul 23;7:CD005627.
In this bibliographic study on 910 women who had gained weight after childbirth, those who opted for physical exercise lost hardly any more weight (-0,10 kg) than those who did no exercise. On the other hand, the women who went on a weight-reducing diet (-1,70 kg) and those who did exercise as well as dieting (-1,93 kg) lost more weight than those who did neither. Although adding exercise to a diet did not greatly enhance the total weight loss, it improved these women’s cardiorespiratory performances and preserved their lean body mass. These interventions had no effect on the breast-feeding process.
Rôle des protéines et des acides aminés dans la synthèse ou l’épargne de masse maigre après exercice de résistance ou déficit énergétique chez l’homme. (Role of protein and amino acids in promoting lean mass accretion with resistance exercise and attenuating lean mass loss during energy deficit in humans). Churchward-Venne TA, Murphy CH, Longland TM, Phillips SM. Amino Acids. 2013 Aug;45(2):231-40.
Amino acids are the main regulators of muscle protein turnover. Their ingestion stimulates the synthesis of muscle protein and inhibits its breakdown, resulting in a processs of lean body mass accretion which continues for several hours. This process requires the ingestion of 1.8g/kg of protein per day. When this requirement is met prior to resistance exercise, the muscle mass and strength improve even more conspicuously. In people on low-energy diets, a daily protein intake of at least 1.2 to 2.3g/kg is necessary to ensure that the lean body mass is spared. In addition to resistance exercice, muscle-building requires a protein intake of approximately 20 to 25g at least 4 times per day in the case of young people and 35 to 40g in that of older people.
Homéostasie calcique et réponse métabolique de l’os à des régimes riches en protéines durant un déficit énergétique chez des hommes jeunes en bonne santé : un essai contrôlé randomisé. (Calcium homeostasis and bone metabolic responses to high-protein diets during energy deficit in healthy young adults: a randomized controlled trial.) Cao JJ, Pasiakos SM, Margolis LM, Sauter ER, Whigham LD, McClung JP, Young AJ, Combs GF Jr. Am J Clin Nutr. 2014 Feb;99(2):400-7.
Taking a low-calorie, high-protein diet for 31 days affects neither protein homeostasis nor bone quality as long as the subjects’ calcium and Vitamin D intake is sufficiently high. This finding was obtained on 32 male and 7 female subjects taking up to 3 times more protein than the recommended daily level of 0.8g/kg. After 31 days on this diet, the subjects with the highest daily protein intake (2.4g/kg) had lost more fatty mass and less lean mass than the others. The protein intake had no effect on the urinary calcium excretion or retention levels. No changes were observed in either the bone turnover markers (BAP, IGF-1, PTH and TRAP) tested or the bone mineral density, whereas the urinary pH levels decreased with the amount of protein ingested.