Nutrition provides the building blocks our body needs, including energy to move for physical activity and metabolic adaptations that occur after exercise. Similarly, those who are physically active are more likely to eat a healthier diet [1]. As an athlete, it’s easy to see this reciprocal relationship; but can we simultaneously administer physical activity and nutrition interventions in populations that are not athletes? More specifically, can we use these modalities together in clinical populations?

The answer is yes. Multimodal interventions constitute two or more modalities aimed at improving outcomes. While these types of interventions do not necessarily have to include nutrition and exercise, this approach is highly effective, especially when the goal outcome is increasing or maintaining muscle. Exercise has anabolic and anti-catabolic effects, but a net protein balance occurs only when sufficient energy and protein is consumed after exercise [2]. The theoretical rationale for using these interventions in clinical populations is that many patients have systemic inflammation, insulin resistance, and muscular disuse – all of which can be ameliorated through physical activity and nutritional strategies (especially those with high calories and protein). Indeed, studies in older individuals, individuals who are obese or have HIV/AIDs or chronic obstructive pulmonary disease, and healthy adults undergoing prolonged bedrest show that while nutrition supplementation might promote muscle anabolism and strength, adding exercise is even more effective [3].

Clearly, clinical populations have diverse nutrition needs, functional limitations, and disease status that might impact the feasibility and efficacy of such integrative interventions. Inclusion criteria must be carefully selected in order to observe any statistical impact. For example, in critically ill patients, there is a possibility that inclusion of “severely ill” individuals might make statistical or clinical impact impossible to detect, since these patients experience such high mortality because of their condition. Conversely, if a patient’s hospital stay is short (i.e. <4 days), then muscle atrophy might not develop, again negating the benefits of an intervention [3]. Like a clinical trial in any population, the primary outcome must be carefully selected, the intervention should be clear and feasible, and statistical tests must be robust.

Interventions like the MENAC trial are implementing nutrition, exercise, and anti-inflammatory interventions in individuals with cancer cachexia, a population that is likely to lose muscle and have significant nutrition impact symptoms. In the pilot phase II study, patients on the intervention arm gained weight while the control group lost weight (p<0.001); there was also a trend indicating the control arm might have lost more muscle [4]. The phase III trial is currently underway in multiple sites across Europe, Canada, and Australia.

Dietitians will play a crucial role in these trials by working with patients and colleagues in other fields to design and implement optimal nutrition throughout the disease trajectory. Future research should highlight the role of the dietitian and elucidate the ideal amount and quality of nutrition to recommend, the mechanisms and outcomes of such interventions, and the patient experience.

References:
1. Loprinzi PD, Smit W, Mahoney S. Physical Activity and Dietary Behavior in US Adults and Their Combined Influence on Health. Mayo Clin Proc. 2014 Feb;89(2):190-8.
2. Poole C, Willborn C, Taylor L, Kerksick C. The role of post-exercise nutrient administration on muscle protein synthesis and glycogen synthesis. J Sports Sci Med. 2010 Sep 1;9(3):354-63
3. Heyland DK, Stapleton RD, Mourtzakis M, Hough CL, Morris P, Deutz NE, Colantuoni E, Day A, Prado CM, Needham DM. Combining nutrition and exercise to optimize survival and recovery from critical illness: Conceptual and methodological issues. Clin Nutr. 2016 Oct;35(5):1196-206.
4. Kaasa S, Solheim T, Laird BJA, Balstad T, Stene G, Bye A, Fallon MT, Fayers P, Kearon K. A randomised, open-label trial of a multimodal intervention (exercise, nutrition, and anti-inflammatory medication) plus standard of cares versus standard of care alone to prevent/attenuate cachexia in advanced cancer patients undergoing chemotherapy. J Clin Oncol. 2015; 33(suppl; abstr 9628)