Evaluation of the reliability and educational quality of YouTube™ videos on sport nutrition topics

Figures & data

Table 1. Sport nutrition scoring system.

Energy intake and body composition

Were the characteristics and goals of adequate energy intake explained?

Was the risk of low energy intake discussed?

Was the importance of body composition, optimal body fat percentage, and its assessment methods presented?

Was the recommended timing for body composition change and weight loss (fat tissue loss) discussed?

Was it discussed that restricted energy intake and a strict weight loss diet could result in micronutrient deficiency?

Were the recommended dietary allowances (RDAs) of micronutrients for athletes presented?

Was the role of micronutrients with key interests (e.g. vitamin D, calcium, iron, and antioxidants) discussed?

Macronutrient intake

Were the adequate carbohydrate intake (% of total energy intake or g/body weight kg) and its dietary sources presented?

Were the adequate protein intake (% of total energy intake or g/body weight kg) and its dietary sources presented?

Were the adequate fat intake (% of total energy intake or g/body weight kg) and its dietary sources presented?

Timing of nutrient intake and hydration

Was adequate fluid intake before, during, and after exercise presented?

Was the method of fluid replacement calculation explained?

Did they warn about the consequences of excessive alcohol consumption on sports goals?

Was the nutrient composition of pre-workout snacks or meals described?

Was the purpose of nutrient and fluid intake during exercise explained?

Were the post-workout dietary goals (e.g. to provide adequate fluid, electrolytes, energy, and carbohydrate intake, replace muscle glycogen, and ensure rapid recovery) explained?

Dietary supplements and ergogenic aids

Were recommendations on dietary supplements introduced?

Were the indications for multivitamin/mineral supplementation explained?

Was the proper use of ergogenic aids discussed?

Was the risk of low intake of nutrients explained?

Special environmental conditions and vegetarian athletes

Did they introduce the specific sport nutrition needs of athletes with special or vegetarian diets or exposed to extreme environmental effects?

Was the importance of a personalized diet and a diet that supports the athlete’s exercise program emphasized?

Role of sport dietitians

Did they discuss the essential role of (sport) dietitians or recommended counseling with them or other professionals?

Figure 1. Selection of videos included in the study.

Table 2. Characteristics of the videos.

	N of views	N of likes	N of comments	View ratio	Like ratio	VPI score	Time duration since upload (in days)
Mean	378348	10411	621	347	11.5	272	1236
Standard deviation	902951	25452	1469	786	31.2	1155	885
Minimum	2	0	0	0.00548	0.00	0.00	365
Maximum	5237458	154463	9733	4316	193	8316	4015

Table 3. Distribution of presenters, video subjects, target population, and source of upload of the included sport nutrition videos.

		n	%
Presenter of the videos
	dietitian	26	22.8
	other healthcare professional	23	20.2
	trainer	25	21.9
	athlete	29	25.4
	laymen, influencer	4	3.5
	other professional	7	6.1
Content of the videos	nutrition for health and wellness	38	33.3
	energy and nutrient needs	8	7.0
	the training diet	25	21.9
	special diets	20	17.5
	nutritional strategies for body composition change	11	9.6
	sport foods	12	10.5
Target population of videos	endurance athletes	28	24.6
	young athletes	6	5.3
	strength athletes	2	1.8
	team sports	5	4.4
	martial arts	3	2.6
	athletes in general	28	33.3
	recreational athletes in general	26	22.8
	special target group (women, men, aging athletes)	6	5.3
Source of upload	academy	4	3.5
	clinics	3	2.6
	sports institutes	17	14.9
	for-profit organizations	30	26.3
	nonprofit organizations	10	8.8
	personal users’ profile	40	35.1
	professional organizations	3	2.6
	news channel	7	6.1

Table 4. Results on the reliability and quality measuring scoring systems.

		GQS		JAMAS		DISCERN		SNSS
Mean		3.25		1.15		42.9		4.09
Standard deviation		1.02		0.731		11.3		4.39
Minimum		1		0		20		0
Maximum		5		4		72		33

Table 5. Inter-rater reliability for scoring schemes.

	GQS	JAMAS	DISCERN	SNSS
ICC	0.77	NA	0.81	0.66
Cohen’s Kappa coefficient	0.78	NA	0.60	0.78

Table 6. Associations between the quality scores and video characteristics.

		GQS	SNSS	DISCERN	JAMAS	VPI
Content of the videos	nutrition for health and wellness	3 (3,4)	5 (3,7)	41.5 (36,56)	1 (1,1)	0.08 (2.14e-5, 10.84)
	energy and nutrient needs	4 (3.37,4.25)	3 (2, 4.5)	50 (43,56)	1 (0,1)	2.85e-4 (7.43e-5, 18.71)
	the training diet	3 (3,4)	4 (2,7)	42 (35,58)	1 (1,2)	0.27 (2.16e-4, 6.55)
	special diets	2.5 (2,4)	1 (0,3)	37 (31,45)	1 (1,1)	0.25 (0.04, 11.92)
	nutritional strategies for body composition change	3 (2,3)	3 (1.5,3.5)	38 (32,40)	1 (1,1)	7.47 (1.02, 212.39)
	sport foods	3 (3,4)	4 (0,3)	42 (35,45)	1 (1,1)	0.90 (0.49, 7.63)
	p	0.002	<.001	0.059	0.695	0.084
Presenter of the videos	dietitian	4 (3.25, 5)	6.5 (4, 8.7)	56 (43,62)	1 (1,2)	0.01 (3.09e-5, 1.54)
	other healthcare professional	3 (3,4)	2 (0,4)	43 (37.5, 51)	1 (1,2)	0.99 (0.16, 52.99)
	trainer	2 (2,3)	3 (1,3)	33 (32,40)	1 (1,1)	12.05 (0.01, 594.93)
	athlete	3 (2,3)	3 (1,4)	38 (34,41)	1 (1,1)	0.64 (0.04, 7.53)
	laymen, influencer	3 (3,3)	3.5 (2)	40.5 (37.3, 43.8)	1.5 (0.75, 2.25)	9.16e-6 (1.61e-6, 0.13)
	other professional	4 (3.5,4.5)	3 (2.7,5.7)	51 (41,57.5)	1 (0.5,1)	0.67 (6.16e-6, 1.14)
	p	<.001	<.001	<.001	0.034	0.004
Source of upload	academy	4.5 (3.7,5)	5.5 (4.2, 6.6)	57.5 (53.3, 59.8)	1 (0.75,1.25)	0.53 (0,2.1)
	hospital	5 (5,5)	19 (12.5,26)	67 (63,69.5)	1 (1,2.5)	0.168 (0.2,0.5)
	sports institutes	4 (3,4)	6 (4,7)	42 (37,47)	1 (1,1)	6.08 (0.1, 28.9)
	for-profit organizations	3 (2,3.7)	2.5 (0.25,3)	38.5 (33.3, 45)	1 (1,1.75)	463.3 (4.82,8315.9)
	non-profit organizations	3 (3,3)	1 (1,2)	46.5 (39.3, 51.5)	1 (1,1)	0.94 (0.03,5.49)
	personal users’ profile	3 (2,4)	3 (2,4.2)	38.5 (33, 49.5)	1 (1,1)	411.8 (0,6728)
	professional organizations	5 (4.5, 5)	9 (7.9)	58 (58,61)	1 (1, 1.5)	0
	news channel	3 (2,3)	1 (0.5, 4)	35 (32,37)	1 (1,2)	78.1 (2.63, 329.4)
	p	<.001	<.001	<.001	0.734	0.020
Type of the argument used in the video	personal experiences, anecdotes, impressions	2 (2,2)	1 (0.5, 2.5)	3 (27.5, 34)	1 (1, 1.5)	1022.57 (1.26,434)
	misbeliefs, experiences, AND scientific evidence	3 (3,3)	3 (1.7, 5)	38 (35,43)	1 (1,1)	255,6 (0,11.9)
	scientific evidence	4 (3.5, 5)	5 (2,8.5)	56 (45,60)	1 (1,2)	9.35 (0,2.04)
	p	<.001	<.001	<.001	0.009	0.004

Kruskal-Wallis test, reported as median (first quartile, third quartile).

Table 7. Associations between the quality scores and quantitative characteristics of the videos.

		DISCERN	JAMAS	GQS	SNSS	VPI
Time duration since upload	r	−0.049	0.114	−0.077	−0.093	−0.066
	p	0.602	0.229	0.414	0.325	0.485
N of views	r	−0.226	0.112	−0.229	−0.200	0.934
	p	0.016*	0.235	0.014*	0.033*	<.001***
N of likes	r	−0.271	0.066	−0.277	−0.236	0.974
	p	0.003**	0.485	0.003**	0.012*	<.001***
N of comments	r	−0.312	0.017	−0.332	−0.310	0.900
	p	<.001***	0.853	<.001***	<.001***	<.001***

r, Spearman’s rho *p < .05, **p < .01, ***p < .001.

Table 8. Correlation matrix between scores.

				VPI		GQS		JAMAS		DISCERN		SNSS
VPI		Pearson’s r		––
		p-value		––
		Spearman’s rho		––
		p-value		––
GQS		Pearson’s r		−0.224		––
		p-value		0.017		––
		Spearman’s rho		−0.247		––
		p-value		0.008		––
JAMAS		Pearson’s r		−0.048		0.186		––
		p-value		0.609		0.048		––
		Spearman’s rho		0.057		0.130		––
		p-value		0.545		0.167		––
DISCERN		Pearson’s r		−0.179		0.855		0.213		––
		p-value		0.056		<.001		0.023		––
		Spearman’s rho		−0.255		0.849		0.136		––
		p-value		0.006		<.001		0.148		––
SNSS		Pearson’s r		−0.119		0.600		0.330		0.551		––
		p-value		0.207		<.001		<.001		<.001		––
		Spearman’s rho		−0.199		0.647		0.154		0.513		––
		p-value		0.034		<.001		0.101		<.001		––

Table 9. Variable and their levels included the ordinal regression.

Variable	Levels of variable
The gender of the presenter	man, woman, both*
Type of media	video created by a user, interview, media news
Type of the video	education, share of experience, advertisement
The environment of the presentation	home, office, kitchen, studio, outdoors, gym, location of training, slides

*both men and women were among the presenters.

Table 10. Results of ordinal regression.

Predictor	Estimate	SE	Z	p	Odds ratio
Presenter (other than dietitian*):
other healthcare professionals	−2.0046	0.825	−2.4285	0.015	0.1347
fitness trainer	−4.0155	0.893	−4.4979	<.001	0.0180
athlete	−3.3855	0.840	−4.0308	<.001	0.0339
laymen	−2.3469	1.334	−1.7591	0.079	0.0957
other professionals	−0.7329	0.956	−0.7663	0.443	0.4805
Target population (in general*):
endurance athletes	0.2677	0.671	0.3988	0.690	1.3069
young athletes	2.0965	1.088	1.9272	0.054	8.1380
strength athletes	−3.5333	1.753	−2.0156	0.044	0.0292
team sports	−1.1223	1.205	−0.9310	0.352	0.3255
martial arts	−2.1147	1.362	−1.5530	0.120	0.1207
fitness	−0.6369	0.707	−0.9010	0.368	0.5289
special	1.1372	1.121	1.0146	0.310	3.1180
Content (nutrition for health and wellness*):
energy and nutrient intake	0.9931	0.961	1.0334	0.301	2.6996
training diet	0.1474	0.679	0.2170	0.828	1.1588
special diets	−2.5313	0.770	−3.2866	0.001	0.0796
nutritional strategies for body composition change	−1.3393	0.838	−1.5981	0.110	0.2620
sport foods	1.0288	0.832	1.2371	0.216	2.7978
Gender of the presenter (man*):
woman	0.3850	0.551	0.6985	0.485	1.4696
both	1.2571	1.290	0.9745	0.330	3.5153
Type of media (by user*)
news	−0.5921	0.983	−0.6025	0.547	0.5531
interview	2.8838	1.204	2.3945	0.017	17.8813
Type of video (share of experience)
education	0.7812	1.066	0.7331	0.464	2.1841
advertisement	−2.1451	3.931	−0.5457	0.585	0.1171
share of experience and advertisement	−0.5490	0.694	−0.7909	0.429	0.5775
education and advertisement	0.9852	0.900	1.0941	0.274	2.6783
Environment of the presentation (home*):
office	1.8588	0.705	2.6379	0.008	6.4159
kitchen	−0.4456	0.950	−0.4689	0.639	0.6405
studio	0.0178	0.822	0.0216	0.983	1.0179
outdoors	1.5022	0.860	1.7475	0.081	4.4914
gym	0.6329	0.976	0.6484	0.517	1.8830
location of training	−1.2974	1.608	−0.8070	0.420	0.2732
presentation	0.2244	0.841	0.2668	0.790	1.2516
Source of upload (personal user profile*):
professional organizations	3.2588	0.787	4.139	<.001	26.018
sports institutes	1.1655	0.526	2.215	0.027	3.207
company	−0.2504	0.457	−0.548	0.584	0.779
non-profit organizations	−0.0927	0.625	−0.148	0.882	0.911
news	−0.9787	0.796	−1.230	0.219	0.376

*Reference level of categories based on expert recommendation.

Table 11. Results of the omnibus likelihood ratio tests.

Predictor	χ^2	df	p
Presenter	30.07	5	<.001
Target population	13.56	7	0.060
Content	22.63	5	<.001
Gender of the presenter	1.23	2	0.540
Type of media	7.42	2	0.024
Type of video	3.03	4	0.553
Environment of the presentation	13.88	7	0.053
Source of upload	30.5	5	<.001