The Safe and Effective Use of Plant-Based Diets with Guidelines for Health Professionals.

Plant-based diets, defined here as including both vegan and lacto-ovo-vegetarian diets, are growing in popularity throughout the Western world for various reasons, including concerns for human health and the health of the planet. Plant-based diets are more environmentally sustainable than meat-based diets and have a reduced environmental impact, including producing lower levels of greenhouse gas emissions. Dietary guidelines are normally formulated to enhance the health of society, reduce the risk of chronic diseases, and prevent nutritional deficiencies. We reviewed the scientific data on plant-based diets to summarize their preventative and therapeutic role in cardiovascular disease, cancer, diabetes, obesity, and osteoporosis. Consuming plant-based diets is safe and effective for all stages of the life cycle, from pregnancy and lactation, to childhood, to old age. Plant-based diets, which are high in fiber and polyphenolics, are also associated with a diverse gut microbiota, producing metabolites that have anti-inflammatory functions that may help manage disease processes. Concerns about the adequate intake of a number of nutrients, including vitamin B12, calcium, vitamin D, iron, zinc, and omega-3 fats, are discussed. The use of fortified foods and/or supplements as well as appropriate food choices are outlined for each nutrient. Finally, guidelines are suggested for health professionals working with clients consuming plant-based diets.

UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research.

Football is a global game which is constantly evolving, showing substantial increases in physical and technical demands. Nutrition plays a valuable integrated role in optimising performance of elite players during training and match-play, and maintaining their overall health throughout the season. An evidence-based approach to nutrition emphasising, a 'food first' philosophy (ie, food over supplements), is fundamental to ensure effective player support. This requires relevant scientific evidence to be applied according to the constraints of what is practical and feasible in the football setting. The science underpinning sports nutrition is evolving fast, and practitioners must be alert to new developments. In response to these developments, the Union of European Football Associations (UEFA) has gathered experts in applied sports nutrition research as well as practitioners working with elite football clubs and national associations/federations to issue an expert statement on a range of topics relevant to elite football nutrition: (1) match day nutrition, (2) training day nutrition, (3) body composition, (4) stressful environments and travel, (5) cultural diversity and dietary considerations, (6) dietary supplements, (7) rehabilitation, (8) referees and (9) junior high-level players. The expert group provide a narrative synthesis of the scientific background relating to these topics based on their knowledge and experience of the scientific research literature, as well as practical experience of applying knowledge within an elite sports setting. Our intention is to provide readers with content to help drive their own practical recommendations. In addition, to provide guidance to applied researchers where to focus future efforts.

Vitamin D supplementation in athletes.

It is well recognized that vitamin D is necessary for optimal bone health. Emerging evidence is finding that vitamin D deficiency can have a profound effect on immunity, inflammation and muscle function. Studies in athletes have found that vitamin D status varies among different populations and is dependent on skin color, early- or late-day training, indoor training and geographic location. Although dietary assessment studies have found that athletes worldwide do not meet the dietary intake recommendations for vitamin D, the most probable reason for poor status is inadequate synthesis due to lack of sun exposure. Studies in athletic populations suggest that maintaining adequate vitamin D status may reduce stress fractures, total body inflammation, common infectious illnesses, and impaired muscle function, and may also aid in recovery from injury. Given that compromised vitamin D status can potentially impact an athlete's overall health and training efficiency, vitamin D status should be routinely assessed so that athletes can be coached to maintain serum 25(OH)D concentration of ≥30 and preferably ≥40 ng/ml. Recommendations will be dependent on the athlete's current 25(OH)D concentration, but can include regular safe sun exposure and/or dietary supplementation combined with increased vitamin D intake.

Antioxidant and Vitamin D supplements for athletes: sense or nonsense?

The idea that dietary supplements can improve athletic performance is popular among athletes. The use of antioxidant supplements is widespread among endurance athletes because of evidence that free radicals contribute to muscle fatigue during prolonged exercise. Furthermore, interest in vitamin D supplementation is increasing in response to studies indicating that vitamin D deficiency exists in athletic populations. This review explores the rationale for supplementation with both antioxidants and vitamin D and discusses the evidence to support and deny the benefits of these dietary supplements. The issue of whether athletes should use antioxidant supplements remains highly controversial. Nonetheless, at present there is limited scientific evidence to recommend antioxidant supplements to athletes or other physically active individuals. Therefore, athletes should consult with their health care professional and/or nutritionist when considering antioxidant supplementation. The issue of whether athletes should supplement with vitamin D is also controversial. While arguments for and against vitamin D supplementation exist, additional research is required to determine whether vitamin D supplementation is beneficial to athletes. Nevertheless, based upon the growing evidence that many athletic populations are vitamin D deficient or insufficient, it is recommended that athletes monitor their serum vitamin D concentration and consult with their health care professional and/or nutritionist to determine if they would derive health benefits from vitamin D supplementation.

Effects of endurance running and dietary fat on circulating ghrelin and peptide YY.

Ghrelin and peptide YY (PYY) are newly recognized gut peptides involved in appetite regulation. Plasma ghrelin concentrations are elevated in fasting and suppressed following a meal, while PYY concentrations are suppressed in fasting and elevated postprandially. We determine whether ghrelin and PYY are altered by a low-fat, high-carbohydrate (10% fat, 75% carbohydrate) or moderate-fat, moderate-carbohydrate (35% fat, 50% carbohydrate) diet and; whether these peptides are affected by intense endurance running (which is likely to temporarily suppress appetite). Twenty-one endurance-trained runners followed a controlled diet (25% fat) and training regimen for 3 days before consuming the low-fat or isoenergetic moderate-fat diet for another 3 days in random cross-over fashion. On day 7 runners underwent glycogen restoration and then completed a 90-minute pre-loaded 10-km time trial on day 8, following a control breakfast. Blood samples were obtained on days 4 and 7 (fasting), and day 8 (non-fasting) before and after exercise for analysis of ghrelin, PYY, insulin and growth hormone (GH). Insulin, GH, Ghrelin and PYY changed significantly over time (p < 0.0001) but were not influenced by diet. Ghrelin was elevated during fasting (days 4 and 7), while insulin and PYY were suppressed. Following the pre-exercise meal, ghrelin was suppressed ~17% and insulin and PYY were elevated ~157 and ~40%, respectively, relative to fasting (day 7). Following exercise, PYY, ghrelin, and GH were significantly (p < 0.0001) increased by ~11, ~16 and ~813%, respectively. The noted disruption in the typical inverse relationship between ghrelin and PYY following exercise suggests that interaction of these peptides may be at least partially responsible for post-exercise appetite suppression. These peptides do not appear to be influenced by dietary fat intake.