1.
Relationship between energy availability, energy conservation and cognitive restraint with performance measures in male endurance athletes.
Jurov, I, Keay, N, Hadžić, V, Spudić, D, Rauter, S
Journal of the International Society of Sports Nutrition. 2021;18(1):24
-
-
-
Free full text
Plain language summary
Athletes who do endurance exercise sometimes experience low energy availability which can affect their performance. Low energy availability may lead to a syndrome called Relative energy deficiency in sports. This cross-sectional controlled study assessed the pre-race energy availability in twelve lean, healthy endurance athletes without pre-existing signs of relative energy deficiency. Results showed that two-thirds of the participants had low mean energy availability. Lower energy availability was associated with higher energy expenditure. Participants in the study deliberately restricted their energy intake to achieve an optimal body composition. This may have led to energy conservation in participants. However, the study failed to show any associations between energy conservation and energy availability. There is a need for more robust studies to determine the true cut-off value of energy availability in male endurance athletes. Healthcare professionals can use the results of this study to understand the need for eating behaviour screening to reduce disordered eating in endurance athletes and the clinical applicability of energy conservation assessment.
Abstract
BACKGROUND Low energy availability in male athletes has gained a lot of attention in recent years, but direct evidence of its effects on health and performance is lacking. The aim of this research was to objectively measure energy availability (EA) in healthy male endurance athletes without pre-existing relative energy deficiency signs during pre-race season. METHODS Twelve trained endurance athletes (performance level 3, 4, and 5) participated in the cross-sectional controlled laboratory study. Fat-free mass, exercise energy expenditure, and energy intake were measured to calculate EA. Resting energy expenditure was measured and estimated to assess energy conservation. Three specific performance tests were used to assess endurance, agility, and explosive strength performance. For psychological evaluation, the Three Factor Eating Questionnaire and a short Well-being questionnaire were completed. RESULTS Mean EA was 29.5 kcal/kg FFM/day. The majority (66.6%) had EA under the threshold for low EA in females. Critical cognitive restraint (≥13) was reported by 75% of participants. There were no differences in performance, blood values, or psychological evaluation when subjects were divided into two groups divided by EA = 30 kcal/kg FFM/day. Cognitive restraint was negatively associated with measured resting energy expenditure and energy conservation (r = -.578, p = .025 and r = -.549, p = .032, respectively). CONCLUSIONS The mean EA measured in this study supports the theory that the threshold for low EA in endurance male athletes might be under the threshold for females. In addition, we confirmed cognitive restraint could be useful for early detection of energy conservation. The high cognitive restraint as measured in our sample stressed the need of eating behavior screening in endurance athletes in order to reduce risk of any disordered eating patterns.
2.
Food-specific IgGs Are Highly Increased in the Sera of Patients with Inflammatory Bowel Disease and Are Clinically Relevant to the Pathogenesis.
Xiao, N, Liu, F, Zhou, G, Sun, M, Ai, F, Liu, Z
Internal medicine (Tokyo, Japan). 2018;57(19):2787-2798
-
-
-
Free full text
Plain language summary
Inflammatory bowel disease (IBD) is an umbrella term incorporating ulcerative colitis (UC) and Crohn’s disease (CD). The exact reasons for the development of IBD are still being debated, however food allergy has been implicated. Diagnosis of food allergy is normally performed looking at the body’s immediate immune response, however the delayed immune response may be of importance in IBD. This study of 301 patients with IBD and 178 healthy controls aimed to look at the delayed immune response of individuals with IBD following the introduction of certain foods. It also looked at the efficacy of a drug treatment, infliximab (IFX) on this immune response. The results showed that the delayed immune response to egg, milk, wheat, corn, rice, tomato, codfish, and soya was increased in those with CD compared to those with UC and healthy control. Infliximab treatment was effective in suppressing this immune response in individuals with CD. It was concluded that in individuals with IBD, measuring the delayed immune response to foods may be an important diagnosis and management tool. This study could be used by healthcare professionals to understand that measuring the immediate immune response to certain foods in individuals with IBD, may not be sufficient. Measuring the delayed immune response in combination with the immediate immune response may give a better picture of foods which should be avoided in those with IBD. Infliximab treatment may be an effective treatment in patients with IBD and a delayed immune response to certain foods.
Abstract
Objective Dietary antigens are common luminal antigens in the gastrointestinal tract and have been considered to contribute to the pathogenesis of inflammatory bowel disease (IBD). We analyzed the levels of food-specific IgGs against a variety of dietary antigens, explored the clinical relevance of food allergy to the pathogenesis of IBD, and investigated whether or not infliximab (IFX) treatment could regulate the immune responses induced by dietary antigens. Methods A total of 301 IBD patients, including 201 patients with Crohn's disease (CD) and 100 patients with ulcerative colitis (UC), were recruited, and their serum food-specific IgGs against 14 food antigens were detected by a semi-quantitative enzyme linked immunosorbent assay (ELISA). Total serum IgG and IgE levels were measured by immunonephelometry and fluorescent enzyme immunoassay, respectively. Simultaneously, the relevant medical records and clinical data were collected for further analyses. Results Food-specific IgGs against egg, milk, wheat, corn, rice, tomato, codfish, and soybean antigens were found to be significantly increased in the sera of CD patients compared with UC patients and healthy controls (p<0.01). The levels of total serum IgG and IgE were also significantly higher in CD patients than in healthy controls (p<0.01). The titers of corn- and tomato-specific IgGs were found to be significantly correlated with total serum IgG in CD patients (p<0.05), while the titers of egg-, milk-, and wheat-specific IgGs were correlated with total serum IgE (p<0.05). Interestingly, IFX therapy was able to down-regulate the food-specific IgG-mediated immune response markedly in active CD patients. Conclusion Food-specific IgGs against egg, milk, wheat, corn, rice, tomato, codfish, and soybean are highly increased in the sera of CD patients. IFX treatment was able to down-regulate the levels of food-specific IgGs by suppressing intestinal inflammation and promoting mucosal healing. Therefore, food-specific IgGs may serve as an important approach in the diagnosis and management of food allergy in IBD.
3.
Beneficial Effects of a Dietary Weight Loss Intervention on Human Gut Microbiome Diversity and Metabolism Are Not Sustained during Weight Maintenance.
Heinsen, FA, Fangmann, D, Müller, N, Schulte, DM, Rühlemann, MC, Türk, K, Settgast, U, Lieb, W, Baines, JF, Schreiber, S, et al
Obesity facts. 2016;9(6):379-391
-
-
-
Free full text
Plain language summary
Recent findings have suggested that the composition of the gut microbiome plays an important role in energy balance and metabolism. The aim of this study was to examine if weight loss altered the gut micriobiota diversity and to determine whether these changes were sustained during a weight maintenance period. Dietary intervention included a very low calorie diet (800 kcal/day) for three months followed by a weight maintenance period for three months. This study consisted of three groups – an intervention of 18 obese adults, a control of 13 lean adults and a second control of 13 obese adults. This study found that a very low calorie diet intervention in obese humans over a three-month period resulted in a significant change in microbiome diversity and metabolism, however these changes diminished during the weight maintenance period. Based on these findings, the authors suggest that nutritional components may exert a stronger effect on the human gut microbiome than changes in body weight or metabolism.
Abstract
OBJECTIVE In the present study, we examined the effect of a very low-calorie diet(VLCD)-based obesity program on human gut microbiome diversity and metabolism during weight loss and weight maintenance. METHODS Obese subjects underwent 3 months of VLCD followed by 3 months of weight maintenance. A lean and an obese control group were included. The microbiome was characterized by performing high-throughput dual-indexed 16S rDNA amplicon sequencing. RESULTS At baseline, a significant difference in the Firmicutes/Bacteroidetes ratio between the lean and obese individuals was observed (p = 0.047). The VLCD resulted in significant alterations in gut microbiome diversity from baseline to 3 months (p = 0.0053). Acinetobacter represented an indicator species for the observed effect (indicator value = 0.998, p = 0.006). Metabolic analyses revealed alterations of the bacterial riboflavin pathway from baseline to 3 months (pnom = 0.0078). These changes in diversity and bacterial metabolism induced by VLCD diminished during the weight maintenance phase, despite sustained reductions in body weight and sustained improvements of insulin sensitivity. CONCLUSION The present data show that a VLCD is able to beneficially alter both gut microbiome diversity and metabolism in obese humans, but that these changes are not sustained during weight maintenance. This finding might suggest that the microbiome should be targeted during obesity programs.