What is a dietary supplement?

A dietary supplement is a product intended for ingestion that contains a “dietary ingredient” intended to add further nutritional value to (supplement) the diet. A “dietary ingredient” may be one, or any combination, of the following substances:

• a vitamin
• a mineral
• an herb or other botanical
• an amino acid
• a dietary substance for use by people to supplement the diet by increasing the total dietary intake
• a concentrate, metabolite, constituent, or extract

Dietary supplements may be found in many forms such as tablets, capsules, softgels, gelcaps, liquids, or powders. Some dietary supplements can help ensure that you get an adequate dietary intake of essential nutrients; others may help you reduce your risk of disease.

It should be noted that any claims a manufacturer or individual makes about a supplement might change its classification.

Researchers have also differentiated “nonvitamin, nonmineral supplements” (NVNM) as those primarily consisting of herbal, botanical, protein/amino acid, brewer’s yeast, and shark cartilage and a variety of other plant-based and nonplant dietary supplements such as enzymes and fish oil.

In competitive sports specifically, there are both “accepted” and “illegal/banned” substances, including some supplements.

In an interesting quandary for the field of performance enhancement, many supplements marketed to athletes contain banned substances – either overtly or because of impurities in these supplements. Researchers bought supplements from 215 suppliers in 13 countries testing 634 nonhormonal supplements. A meaningful % of the supplements (14.8%) contained substances that would lead to a positive drug test.

Problems also abound for individuals who use supplements to achieve added weight loss and/or muscle gain (or improved recovery after workouts) from their exercise programs.

Considering a worldwide ongoing obesity epidemic, it is not surprising that many individuals are seeking new ways to lose weight. Supplements promise, though probably seldom deliver, a magic bullet of sorts: easy, hassle-free weight loss with little in the way of dietary sacrifice.

Athletes undoubtedly account for a large portion of those who use dietary supplements, and there are a variety of products that are marketed directly at competitive athletes. Elite athletes tend to take supplements more commonly than college or high school athletes, and women used supplements more often than men.

Considering elite Canadian athletes participating at the Atlanta and Sydney Olympics, respectively, prevalence rates of 69% and 74% were reported. Vitamin use was most common (58-66%), whereas nutritional supplements were used commonly (Atlanta: 35% men, 43% women, Sydney: 43% men, 51% women) often consisting of creatine, and/or amino acid supplementation. Based on results overal, it appears that supplementation increases with the competitive level of the sport and is somewhat higher for female athletes.

There are 3 specific categories: supplement use to build muscle for aesthetic purposes or body image concerns, and supplement use to lose weight for aesthetic purposes, body image concerns, or health.

There is a behaviouristic explanation possible for the use of supplements in that athletes’ use may lead to reward contingencies (eg: more prize money), thereby driving future behaviour. Similarly, supplements that build muscle or promote weight loss could produce rewarding results. Also, there are undoubtedly social influences at work considering that coaches, parents, athletic trainers, and peers have been reported to be influential regarding the decision to take supplements.

Operant conditioning: focuses on the manner in which our behaviour and action are influenced by the outcomes that follow them. Derived from the behaviouristic research tradition, the sum of findings in this area dictate that some outcomes/stimuli strengthen the behaviour that preceded them, and others weaken the likelihood of the behaviour that preceded them. Outcomes that increase the likelihood of behaviour are known as reinforcers, and those that decrease the likelihood of behaviour are known as punishment. In the present context, prize money, praise from others, or rewards due to improved performance are reinforcers of the behaviour to take supplements. Because most legal supplements likely would not produce dramatic sport performance gains, muscle mass gains, or weight loss results, perhaps the best explanation for use is found in other theories. Behaviouralistic explanations, however, might be highly applicable considering the use of illegal substance such as steroid use.

When trying to change attitudes about whether supplements are good or bad, it is likely that some individuals are more persuasive than others. Individuals are more persuasive if they are seen as trustworthy or having pertinent expertise. The supplement industry often uses exactly such a strategy to help market their products. University research and “expert” sport and exercise nutritionists are increasingly being used to support the efficacy of performance enhancing, muscle building, or weight loss supplements. Consumers should consider, however, that a company may contract with 3 universities to test their products and report only the results of the positive outcomes in their advertisements.

Achievement Goal theory: within this theory, it is assumed that there are differences in the manners by which athletes judge their competence or success. Individuals who are task-oriented tent to judge their success on the basis of personal improvement, whereas those who are ego-oriented tent to judge their success on the basis of social comparison with others. Task-oriented individuals typically view personal ability as changeable and exhibit strong motivation regardless of their perceptions of competence. Those who are ego-oriented, tend to view ability as more static and are thus more likely to engage in questionable strategies to ensure winning and would be expected to engage in more frequent doping activities and perhaps a greater willingness to use supplementation strategies.

Body image and eating disorders: Obesity rates have dramatically increased over the past few decades, a similar increase in the ideal body size has not occurred in the female population. In fact, the “ideal” waist size for females may have become unhealthily small. Because of these 2 contradictory trends, it is no surprise that the use of supplements targeted at weight loss has increased dramatically during this same time period. The nation is getting heavier and feeling worse about it, especially the female segment. In one survey, research showed that among women at risk for eating disorders approximately 65% engage in frequent use of “diet pills”.

Adonis complex: There is an opposing set of preoccupation afflicting males termed the Adonis complex, which seems to be afflicting boys and men more specifically during the last few decades. These individuals may compulsively lift weights or exercise, engage in steroid abuse, elect to undergo plastic surgery, or suffer from eating disorders or body dysmorphic disorders, all in attempts to gain muscle mass, change fat distribution, or otherwise alter their appearance to some ideal.

In one of the seminal works in this area, Pop and colleagues interview 108 bodybuilders (55 steroid users and 53 non-steroid users) and found a higher than normal incidence of anorexia nervosa (2.8%) and a surprising incidence of ‘reverse anorexia’ (8.3%), with some of the respondents believing that they appeared small and weak despite their large, muscular appearance. The latter finding indicated that some of these bodybuilders exhibited unusual preoccupations with their appearance. Such pathological preoccupation with muscularity has been termed muscle dysmorphia. As an important link to potential supplement use or abuse, in Pope and colleagues’ research all of the bodybuilders indicating muscle dysmorphia (then termed ‘reverse anorexia’) were in the sample of steroid users, and many reported that the symptoms of muscle dysmorphia were a factor that led to steroid use. As an indication of the degree of this obsession, individuals with this affliction have reported lifting weights for hours a day while sacrificing other areas of their lives. For example, some of these individuals reported earning degrees in business, law or medicine but did not pursue a career or gave up a career in these areas because they needed more time to lift weights. Recent research indicates that bodybuilders suffering from higher levels of muscle dysmorphia are more likely to experience body dissatisfaction, social physique anxiety, and use muscle-building or fat-reducing targeted supplements. At present there is some evidence that supplement use is greater among individuals with muscle dissatisfaction or muscle dysmorphia. It also appears that illegal supplement use may accompany muscle dysmorphia as data indicate that 1 million or more US males have used these substances primarily to promote muscle growth as opposed to performance enhancement purposes. Finally, it should also be noted that research find that some men have become preoccupied with fat, as opposed to muscle, and, in contrast to attempting to gain weight, may develop eating disorders. This suggests that body image concerns among males may drive some to attempt obsessively to build muscle mass whereas others may obsessively work to lose fat. In both cases it is likely that legal or illegal supplementation is a common means to achieve such goals. 

An abstract from “Psychology of Supplements in Sport and Exercise – Motivational Antecedents and Biobehavioral Outcomes” by Rafer Lutz and Shawn Arent