Basketball is a fast-paced group activity, represented by irregular episodes of high-force movement repeated over a prolonged time, and players utilize both aerobic and anaerobic energy systems. As a competitive team sport, basketball requires vigorous preparation for the very high-intensity rivalry games. A professional basketball player trains 2 to 3 h a day, 4 to 6 times each week, making basketball a high calorie-burning sport with significant physiological demands.
The Lebanese Basketball federation (FLB) organizes the top-tier professional men’s and women’s basketball teams in Lebanon. The Lebanon men’s and women’s national basketball teams have been considered among the top teams in Asia. National championships are organized annually by the FLB, with playoffs played and the winning team receiving a national cup. Players have a long pre-season and a normal season composed of 25 to 30 games in addition to tournament games. The two teams that advance play a best of four out of seven games in the final to determine the league champion. The season starts in December and ends in May.
The American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine recommend appropriate selection of food, fluids, and supplement choices as well as optimization of the composition and timing of intakes of macronutrients, micronutrients, and fluid throughout the day by athletes for provision of sufficient energy, replenishment of glycogen stores, maintenance of circulating blood glucose levels, build, maintenance and repair of tissue and ultimately enhancement of athletic performance, recovery from exercise and exercise-induced injury [1]. These recommendations are based on the best evidence available integrated with expert judgment. Recent studies found that a planned scientific dietary approach helped non-elite runners and endurance-trained cyclists complete a marathon run and a time trial faster, respectively [2, 3]. Studies showed that carbohydrate (CHO) loading not later than 4 h prior to, CHO consumption between 30 and 80 g/h during and within 2 h after endurance exercise significantly delay onset of fatigue and improve endurance performance [4,5,6,7]. This is attributed to the fact that inappropriate carbohydrate intake or loading prior to endurance exercise causes depletion of glycogen, the body’s predominant source of energy during moderate to high-intensity exercise. In a study that aimed to influence dietary intake and body composition to improve athletic performance of elite and subelite male Australian football and soccer players, adequate dietary intake was indicated to be positively correlated with fat-free soft tissue mass [8]. In a study done on nine trained cyclists to compare the effects of a carbohydrate and a carbohydrate-protein supplement on aerobic endurance performance, researchers found that the addition of protein to a carbohydrate supplement enhanced aerobic endurance performance above that which occurred with carbohydrate alone [9]. In a cross-sectional study among 293 Taekwondo players of Kathmandu Metropolitan City, it was shown that fat and energy intake have significant positive correlations with handgrip strength of athletes and energy intake has an independent positive association with athletic performance (β = 0.13, 95% CI: 0.12 = 0.14) [10]. Substantial evidence also exists that micronutrients play an important role in several physiologic processes, including energy production, oxygen transport, bone health, immune function, antioxidant function, fluid balance and build and repair of muscle tissue following exercise, that are crucial for peak endurance exercise performance. Several studies showed that marginal micronutrient deficiency states have potential implications for the overall health of athletes and performance. For example, iron-depleted endurance athletes have shown an impairment in exercise performance in several studies [11, 12]. Calcium losses, produced by a drop in levels of calcium-regulating hormones that results from intense endurance training with insufficient calories to meet training demands, predispose an athlete to stress fractures, osteoporosis and inevitably interfering with sport performance [13]. Female endurance athletes with low energy availability, menstrual dysfunction and low calcium intake are at greatest risk of developing the female athlete triad (disordered eating, amenorrhea, osteoporosis) [14] Similar to the adverse effects of macro- and micro- nutrient deficiencies on athletic performance, dehydration has been associated with increased risk of oxidative stress and compromised exercise performance [15]. Studies showed that fluid losses of 2% or more of body mass is sufficient to cause a noticeable decrease in performance, especially in warm-hot weather [16]. Maintaining proper hydration by drinking beverages containing carbohydrate and electrolytes during and after training or competition by endurance athletes, on the other hand, has been shown to delay fatigue, enhance performance and reduce risks of injury associated with dehydration and sweat loss [17].
Despite the well reported importance of a balanced diet for the athlete’s overall health, athletic performance, recovery from exercise and exercise-induced energy, research suggests that dietary Intake of athletes do not meet sport nutrition recommendations. The bulk of the literature explains this phenomenon by the lack of nutrition knowledge (NK) among athletes and its association with unhealthy dietary habits. In a cross sectional study surveying 73 Brazilian adolescent professional soccer players aged 14–19 years, the study participants showed a low NK (54.6%) and an inadequate intake of fruits, vegetables, dairy, carbohydrates, and micronutrients. In addition, sodium intake was negatively correlated with the three categories of the NK test (Basic NK (BNK), Sports NK (SNK), and Food Pyramid NK (FPNK), and phosphorus and calcium intakes were positively correlated with FPNK and both SNK and Total NK, respectively [18]. In another cross-sectional study done on 293 Taekwondo (TKD) players of Kathmandu Metropolitan City, it was found that more than half (56.3 and 55.6%) had poor NK and nutrition practice scores, respectively. The median energy (2368 Kcal), protein (79.5 g), fat (71.2 g), calcium (416 mg), and iron (7 mg) intake among TKD players were significantly lower than the corresponding Recommended Dietary Allowances for athletes [10]. In a study assessing the dietary intake, NK and hydration status of Irish Gaelic footballers (n = 168), findings suggested that the participants lack NK (40.2 ± 12.4%, n = 24) and had sub-optimal dietary practices. Dietary assessment showed an energy deficit (485 kcal [IQR 751, 6]) (p < 0.001), with carbohydrate intake (3.6 g/kg [IQR 3.0,4.1]) below current guidelines for athletes participating in 1 h moderate intensity exercise per day (5–7 g/kg; p < 0.001). Average vitamin D (3.8 μg [IQR 1.8, 5.5]) and selenium intakes (54.2 μg [47.2, 76.7]) were significantly below the reference nutrient intakes. In addition, a high proportion of athletes also had sub-optimal vitamin A (38.7%), potassium (30.6%), zinc (25.8%), magnesium (19.4%) and calcium (12.9%). Pre-exercise hydration status (median urine specific gravity 1.010 [IQR 1.005, 1.017]) was significantly below the cut-off to represent dehydration (1.020) [19]. In five studies done on Australian athletes to evaluate and compare nutritional intake to current recommendations, the study participants were found to have low NK (answered only 51, 57, 54.5%, 46, 56.9% (professional athletes) /61.3% (semiprofessional athletes) of the Sports NK Questionnaire questions correctly, respectively) and their energy and nutritional intakes of macronutrients (carbohydrate and protein) and some micronutrients (calcium and iron) were incoherent with current recommendations [8, 20,21,22,23]. The associations between poor NK and inadequate energy and nutritional intakes were demonstrated by the moderate positive correlations found between NK scores and meeting estimated energy requirements (r = 0.33, P = 0.03), protein (r = 0.35, P = 0.02), fiber (r = 0.51, P = 0.001, calcium (r = 0.43, P = 0.004 [22] and carbohydrate intakes (n = 41, ρ = 0.32, p = .04) [23]. In a cross-sectional study conducted on a group of 1040 British adults to investigate the relationship between NK and intake of fat, fruit and vegetables, researchers found NK to be an independent predictor of healthy eating habits; specifically, study participants in the highest quintile for NK were found to be almost 25 times more likely to meet current recommendations for fruit, vegetable and fat intake than those in the lowest quintile, after controlling for demographic variables [24]. Similarly, another study involving 21 professional rugby league players found overall NK to be positively correlated to consumption of fruit and vegetables (rs = .52, p < .05). In addition, a significantly higher percentage of rugby players in the good nutritional knowledge group reported consuming starchy foods, fruit & vegetables, oily fish and milk more frequently whereas, a higher percentage of players in the poor nutritional knowledge group reported more frequent consumption of fizzy drinks and squash [25]. A cross-sectional study done to evaluate the NK and dietary practices of postmenopausal women showed moderate positive significant correlations between NK and milk score, servings of high-calcium foods and food frequency score and a negative significant correlation between NK and the use of carbonated beverages [26]. Another study showed positive significant correlations of NK with intake of cereals (r = 0.30) and fruit and vegetables (r = 0.33) and negative significant correlations of NK with intake of fats and oils (r = − 0.38), tea and coffee (=r-0.31) and junk foods (r = − 0.29) [27]. A study done to assess dietary habits and practices of 383 NCAA Division I athletes, found that those who reported working with a sports dietitian for the purpose of dietary planning had a better understanding of the need to periodize nutrient intake by adjusting caloric intake according to demands of the training cycle (47.12% vs. 32.85%), were more likely to have school-provided boxed meals while on team trips (21.29% vs. 6.77%), and also less likely to consume fast food prior to practice or competition while on team trips (9.90% vs. 19.55%) [28]. Research also supported an association between inadequate NK and risk of eating disorders. In a longitudinal study done to assess NK, attitudes and eating behavior of 22 runners, it was found that runners with acceptable eating attitude test (EAT) scores (at low risk of eating disorders) had a mean of 70% on the NK test and consumed an average of 1781 kcal, while those with high EAT scores (at high risk of eating disorders) had a mean of 57% on the NK test and consumed an average of 1295 kcal daily [29]. In addition, multiple randomized clinical trials showed that nutrition education has been shown to be effective in improving dietary habits of athletes. In a recent experimental study that aimed to determine the effects of sports nutrition education intervention program on improvements in sports NK, attitude and practice, and dietary intake among Malaysian team sports athletes, significant increases in the intervention group’s (IG’s) mean scores for knowledge, attitude and practice compared to decreases in the respective mean scores of the control group were observed. In addition, significant improvements were found in the IG’s total energy intake, total carbohydrate and total protein intake compared to those of the control group [30]. In another trial done to evaluate the effectiveness of nutritional counselling in improving the athlete’s NK, body composition and eating behavior, it was found that the intervention resulted in increased NK, lean body mass, intake of vegetables and fruits and decreased intake of sweets and oils [31] . In another experimental study done to assess the effectiveness of nutrition education in active middle school and high school students, significant improvements on questions about protein and exercise, and dietary supplement use knowledge were observed in both middle and high school students. In addition, knowledge on general nutrition, fiber, hydration, vitamins and minerals improved significantly in high school students only, whereas, knowledge on carbohydrates improved significantly in middle school students only [32] . An intervention study investigating the effect of a six-month nutrition education program on eating behavior and skeletal loading exercise in competitive male road cyclists at risk for relative energy deficiency in sports, found those with increased energy availability over the 6-month intervention period to have improved bone health and race performance than those with reduced energy availability [33].
Acquiring adequate and credible nutrition information is important as it would shape the athlete’s NK and, therefore, could inform nutritional choices which, in turn, would mold the athlete’s physical health, athletic performance, recovery from exercise and exercise-induced injury. Several studies showed that the nutrition information sources are not equally accurate and therefore do not all have a positive impact on NK. In cross-sectional studies done to examine the relationship between sources of nutrition information and NK, it was found that use of healthcare professionals, nutritionists/dietitians, books and/or magazines, or newspapers as a source of nutrition information was positively associated with NK [34, 35], whereas, use of physicians/nurses and television/radio as sources of nutrition information had a negative impact on NK [36]. The unavailability of sports nutritionists in the athletes’ clubs makes athletes often turn to readily accessible sources of sports nutrition information such as the coaches, assistant coaches (ACs), athletic trainers (ATs), strength and conditioning coaches (SCCs), internet, parents/friends and social media. In a cross-sectional study done to assess the NK status of 100 athletes enrolled in a NCAA Division II sport, athletes reported school (25%), online sources (24%), parents/friends (19%), personal experience (10%), personal research (10%), coaches (8%) or ATs (4%) as their primary source of nutrition information [36]. In another survey involving 185 athletes enrolled in NCAA Division I, II, and III institutions, athletes indicated their top three choices of nutrition information as SCC (16.2%), AT (11.4%) and coach (7.7%) [37]. In a cross-sectional study that surveyed 207 Iranian basketball and football college players, the players reported coach as the primary nutrition information source (89.4%), television, radio or the Internet (59.9%) as the second most and a family member or friend (27.5%) as the third most popular source of nutrition information [38] . In a study involving NCAA division I, II or III collegiate cross-country runners, runners reported that their top four sources of nutrition information were magazines, parents, coaches, and teammates [39]. In a survey involving 45 male NCAA Division I college football players, the top two sources of nutrition information reported by the players were SCCs and teammates &/or friends & family [40]. In a cross-sectional study involving 200 Malaysian university students, the results showed that the main sources of nutrition information for athletes were the internet (82%), newspapers or magazines (70%), families or friends or neighbors (65%), television (60%) and coaches (52%) [41]. These readily accessible nutrition information sources, however, are potentially unreliable.
The NK of coaches, ACs, ATs and SCCs, for instance, is often insufficient for proper guidance and may lead to the dissemination of misinformation regarding sports nutrition among athletes. A recent comprehensive review of NK of coaches indicated that key sport nutrition concepts are poorly understood by most coaches [42]. A study done to assess sports NK of coaches, found coaches to have a total mean NK score of 68.4% with less than 30% of the coaches providing correct answers to some general nutrition questions regarding carbohydrates and lipids [43], .In a survey done on five varsity coaches at a Canadian college, researchers found coaches to have low NK (Mean NK with high degree of certainty: 49.5–68.3%), but still made nutrition recommendations to their athletes [44]. In another study involving 303 coaches of women’s sports at all levels of collegiate competition, researchers found that a substantial proportion of coaches engaged in some form of weight management behaviors with their athletes (for e.g., assess body composition (44.4%), encourage to lose weight by restricting intake (29.9%)), despite the fact that about 50% of the athletes have battled with issues associated with eating and weight and that only about one-third of the coaches received formal training in nutrition [45] . In addition, in a survey involving coaches (n = 131); ATs (n = 192), SCCs (n = 71) and athletes (n = 185) at NCAA Division I, II, and III institutions, adequate knowledge was found in only 35.9% of coaches (NK score ≥ 75%) [38] . In another study done on 163 UK coaching certificate level 2 and 3 hockey and netball qualified coaches, the mean total NK score for all coaches was found to be low (35.4% ± 14.8%), with no significant differences found between those who gave and did not give nutritional advice to athletes. In addition, only about one third of the coaches who provided advice received formal nutrition training [46].
Basketball is the most popular sport in Lebanon. Professional basketball players have specific dietary requirements to meet the nutrient needs of regular intensive training and ensure optimal wellbeing [47]. Optimal nutrition not only maintains the athlete’s wellbeing but also fuels the athlete’s physical performance, recovery from exercise and exercise-induced injury [1]. Research, however, suggests that dietary intake of athletes do not often meet sport nutrition recommendations due to inadequate NK. In Lebanon and in contrast to many other countries, D1B players do not get any nutrition education as part of their training schedule or school curriculum and there is no established position for sports nutritionists in basketball clubs in Lebanon. Therefore, basketball players are likely to get their nutrition information from a variety of easily available, yet potentially unreliable, sources. The aims of the study are to: 1) assess the prevalence of inadequate NK; 2) recognize the gaps in NK 3) pinpoint the main sources of nutrition information 4) understand perceptions on sports nutrition and the impact of dietitian/nutritionist on diet and performance and 4) identify the independent predictors of inadequate NK, among division I basketball players in Lebanon.
To our knowledge, the present study is the first to evaluate the NK status of D1B athletes/coaches in Lebanon. By assessing the prevalence of inadequate NK and identifying the gaps in NK and the main sources of nutrition information in this group of athletes, the need to take action by team managers, by budgeting for hiring sports nutritionists or inviting sports nutritionists to the sports club to educate D1B athletes/coaches and fill in these gaps, and school managers, by integrating nutrition into the school curriculum, may become evident. This will, in turn, help enhance the athletes’ physical health and performance.