Applied Physiology, Nutrition, and Metabolism
ISSN / EISSN : 1715-5312 / 1715-5320
Published by: Canadian Science Publishing (10.1139)
Total articles ≅ 2,962
Latest articles in this journal
Published: 29 September 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2022-0219
This research estimated and characterized advertising expenditures on food products heavily advertised on youth-appealing television stations in Canada in 2019, overall, by media, and by food category, and to compare expenditures in two policy environments (Quebec and the rest of Canada, excluding the territories), and on “healthier” versus “less healthy” products. Advertising expenditure estimates for 57 selected food categories promoted on television, radio, out-of-home media, print media, and popular websites were licensed from Numerator. Sixty-one products or brands were identified as heavily advertised on youth-appealing stations and classified as “healthier” or “less healthy” based on a nutrient profile model proposed by Health Canada. Total expenditures and expenditures per adolescent capita were calculated. Approximately $110.9 million was spent advertising food products heavily advertised to adolescents in Canada in 2019, with television accounting for 77% of total expenditures and fast food restaurants accounting for 51%. Most expenditures (77%; $80.6 million) were devoted to advertising “less healthy” products. In Quebec, advertising expenditures on examined products were 23% lower per capita ($45.15/capita) compared to the rest of Canada ($58.44/capita). Advertising expenditures in Quebec were lower for energy drinks (-47%; -$0.80/capita) and candy and chocolate (-41%; -$1.00/capita), and higher for yogurt (+85; +$1.22/capita) and portable snacks (+25%: +$0.15/capita). Quebec’s restriction of commercial advertising directed to children under 13 may explain lower per capita advertising expenditures on some “less healthy” foods heavily advertised to adolescents in Quebec. Nevertheless, this spending remains high in Quebec and nationally. Continued monitoring of these expenditures is warranted.
Published: 29 September 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2022-0051
The accuracy of books as public nutrition resources varies substantially; whether authors of publicly available nutrition books possess related experience, cite scientific evidence, or have other financial incentives has not been assessed thoroughly. This study aimed to determine if publicly available top-selling nutrition books are written by authors who (1) have relevant expertise, (2) cite scientific evidence, and (3) benefit financially in other ways. Best-selling nutrition books were gathered from Amazon Canada. Differences in scientific citations and financial incentives were compared between authors with and without credentials. Authors who were Doctor of Medicine (MD), registered dietitians (RD), chiropractors (DC), or naturopathic doctors (ND) had more in-text citations (56% versus 25%, p=0.014) and cited more scientific articles (83% versus 50%, p=0.0045) compared to all other authors. The majority of authors of publicly-available top-selling nutrition books in Canada did not have MD/RD credentials. Many of the authors promoted their own services or products, regardless of credentials.
Published: 22 September 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2021-0658
The complexity of human milk feeding behaviours may not be captured using simpler definitions of ‘exclusive’ and ‘non-exclusive’ breastfeeding. New definitions have been suggested to describe variation in these behaviours more fully but have not been widely applied. We applied the new definitions to data derived from 3-day human milk feeding diaries. Participants (n=1091) recorded the number, beginning/end time, and modes of feeding of infants aged 3 months. Data were used to create six exclusive groups according to feeding mode(s): 1) human milk at-breast only; 2) human milk at-breast and human milk in a bottle; 3) human milk at-breast and infant formula in a bottle; 4) human milk at-breast and human milk and infant formula mixed in the same bottle; 5) human milk at-breast, human milk in a bottle, and infant formula in a bottle (not mixed); 6) a bottle that sometimes contained human milk and sometimes infant formula (not mixed); never at-breast. Differences in maternal and infant characteristics were examined among groups. Fifty-seven percent fed at-breast only (Group 1). Those in Group 1 spent a similar amount of time feeding directly at-breast (median 132 (IQR 98-172 ) min/day) as those in Groups 2 (124 (95-158)), 3 (143 (100-190)) and 5 (114 (84-142)) (p>0.05) indicating that adding bottle-feeding did not always reduce the time infants were fed at-breast. Applying new suggested definitions to describe human milk feeding behaviours from the mothers’ perspective highlights the complexity of patterns used and warrants further application and research to explore impacts on health outcomes.
Published: 20 September 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2022-0164
Leucine is a critical amino acid stimulating myofibrillar protein synthesis (MyoPS). The consumption of higher leucine-containing drinks stimulates MyoPS, but we know less about higher leucine solid foods. Here we examined the effect of short-term resistance exercise training (STRT) combined with supplementation of a protein and leucine-enriched bar, compared with STRT alone, on integrated (%/d) rates of MyoPS and anabolic protein signaling. In a non-blinded, randomized crossover trial, eight young adults performed four sessions of STRT without or while consuming the study bar (STRT+Leu, 16g of protein containing ∼3g of leucine) for two 4d phases, separated by 2d non-exercise (Rest) washout. In combination with serial muscle biopsies, deuterated water permitted the measurement of myofibrillar protein synthesis and protein signaling phosphorylation. MyoPS during STRT (1.43 ± 0.06 %/d) and STRT+Leu (1.53 ± 0.06 %/d) were greater than Rest (1.31 ± 0.05 %/d), and MyoPS during STRT+Leu (1.53 ± 0.06 %/d) was greater than STRT alone (1.43 ± 0.06 %/d). STRT+Leu increased the ratio of phosphorylated to total mTOR and 4EBP1 compared to Rest. Engaging in STRT increased integrated MyoPS and protein signaling in young adults and was enhanced with increased protein intake derived from a leucine-enriched protein bar. This study was registered at clinicaltrials.gov as NCT03796897.
Published: 15 September 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2022-0195
Exercise and nutrition interventions are often recommended for frailty; however, effective strategies are required for real-world implementation. Our primary aim was to assess the feasibility and acceptability of telephone and virtual delivery of MoveStrong, an 8-week exercise and nutrition program with a 4-week follow-up for older pre-frail and frail adults. A priori criteria for success included: recruitment (≥25/12 weeks), retention at follow-up (≥80%), and adherence to exercise and nutrition sessions (≥70%). We recruited community-dwelling Ontario residents; ≥60 years, ≥1 chronic condition, ≥1 FRAIL scale score. Participants received mailed materials, a personalized exercise program, eleven remote one-on-one training sessions with an exercise physiologist and three online dietitian-led nutrition education sessions. We completed exploratory analyses of secondary outcomes including physical function and dietary protein intake. Semi-structured interviews supported program evaluation. In total, 30 participants were enrolled. 28 (93%) participants completed program and follow-up assessments. Adherence to exercise and nutrition sessions (CI) was 84% (77-91%) and 82% (70-93%) respectively. At program end and follow-up [mean change (CI)], significant improvements were measured in 30-second chair stand test [3.50 (1.12–5.86), 4.54 (1.94–7.13) chair stands] and dietary protein intake [12.9 (5.7–20.0), 9.2 (0.4–18.1) g]. Overall, participants were satisfied with program delivery. Trial registration number: NCT04663685.
Published: 14 September 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2022-0204
Hypoxia negatively impacts aerobic exercise, but exercise testing in hypoxia has not been studied comprehensively. To determine the effects of simulated altitude on the gas exchange threshold (GET), respiratory compensation point (RCP), and maximal oxygen uptake (V̇O2max), 24 participants (mean [SD]; 26  years; 171.6 [9.7] cm; 69.2 [11.9] kg) acclimatized to mild altitude (~1100 m) performed three cycling ramp-incremental exercise tests (with verification stages performed at 110 % of peak power output (PPO)) in simulated altitudes of 0m (SL), 1111m (MILD), and 2222m (MOD), in a randomized order. There were significant effects of condition (i.e., fraction of inspired oxygen [(FIO2]) for GET (p=0.001), RCP (p<0.001), V̇O2max (p<0.001), and PPO (p<0.001). The V̇O2 corresponding to GET and RCP (mL·kg-1·min-1) in MOD (24.1 [4.3]; 37.3 [5.1]) were significantly lower (p0.05) between SL and MILD. For each increase in simulated altitude, V̇O2max (SL: 51.3 [7.4]; MILD: 50.0 [7.6]; MOD: 47.3 [7.1] mL·kg-1·min-1) and PPO (SL: 332 ; MILD: 327 ; SL: 316  W) decreased significantly (p<0.05 for all comparisons). V̇O2max values from the verification stage were lower than those measured during the ramp-incremental test (p=0.017). Overall, a mild simulated altitude had a significant effect on V̇O2max and PPO but not GET and RCP, moderate altitude decreased all four variables, and the inclusion of a verification stage had little effect on the determination of V̇O2max in a group of young healthy adults regardless of the FIO2.
Published: 12 September 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2022-0271
To support Canadians ages 2 years and older in improving their dietary intake, Health Canada released a revised Canada’s Food Guide (CFG) in 2019. This study aimed to explore the knowledge and perceptions of the 2019 CFG among children ages 9–12 years old from Southwestern Ontario. From September–November 2021, interviews were conducted with children by video conference. Thirty-five children (50% girls, 80% White; mean age 9.9 years) participated. Data were analyzed using a hybrid thematic approach with inductive and deductive analyses. Many children expressed a lack of knowledge on certain foods (i.e., plant-based proteins, whole grains, highly processed foods) that are highlighted in the CFG. Children also expressed confusion around food groups, including recommended proportions and categorization of some foods (e.g., dairy products, plant-based proteins). Children generally expressed positive perceptions regarding CFG and its eating habit recommendations, i.e., “Cook more often”, “Eat meals with others”, and “Enjoy your food”, and they suggested strategies to improve adherence to these recommendations, including providing children more responsibility and independence with food preparation tasks and minimizing family time conflicts. Children’s perceptions of the CFG can help inform public health policies and programmatic strategies designed to support children's food choices and eating habits.
Published: 9 September 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2021-0789
Diet plays a role in the pathophysiology and treatment of women with hyperandrogenic menstrual disturbances; however, limited research exists examining components of dietary intake in women with subclinical menstrual disturbances. The aim of this investigation was to evaluate the relationship between diet quality and hormonal status in exercising women with menstrual disturbances. Eighty exercising women with ovulatory menstrual cycles (OV; n=32), women with oligo/amenorrhea without evidence of hyperandrogenism (Oligo/Amen-LowFAI n=28), and women with oligo/amenorrhea and evidence of subclinical hyperandrogenism (Oligo/Amen-HighFAI; n=32) participated in the cross-sectional observational study (Clinical Trial Number NCT00392873). Self-reported menstrual history, resting energy expenditure, body composition, hormonal and metabolic hormone concentrations determined reproductive and metabolic status. Serum androgens and calculated free androgen index (FAI) determined androgen status. The Diet Quality Index International (DQI-I) and the Dietary Inflammatory Index (DII) evaluated quality of diet. Oligo/Amen-HighFAI group had the highest androgen concentrations (p<0.05) and lower DQI-I score compared to OV group and Oligo/Amen-LowFAI (p<0.05). The Oligo/Amen-HighFAI group consumed less of vitamin A, B2, B6, B12, magnesium, and potassium compared to the Oligo/Amen-LowFAI group (all p<0.05). In the women with menstrual disturbances with subclinically elevated androgens, poor diet quality is related to altered hormonal parameters which may have implications for future nutritional treatment strategies.
Published: 29 August 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2022-0179
Rating of Perceived Exertion (RPE) is used to subjectively quantify the perception of physical activity, breathlessness or dyspnea, and leg discomfort (RPElegs) during exercise. However, it is unknown how dyspnea or RPElegs can be influenced by expectations. Thirty healthy, active participants (19 M, 11 F) completed five, 5-minute submaximal cycling trials at 60% peak work rate. We deceived participants by telling them they were inspiring different hypoxic and hyperoxic gases, when in fact they breathed room air. Cardiorespiratory variables were similar between the trials, however dyspnea and RPElegs evaluated with a Borg scale changed in a dose-response manner. When participants believed they were breathing 15% O2, they significantly increased dyspnea +0.70 ± 0.2 units (p=0.03) compared to room air, whereas RPElegs was unchanged +0.35 ± 0.1 units (p=0.70). When comparing 15% O2, to the 23% hyperoxic condition, where participants significantly increased their dyspnea +1.05 ± 0.4 units (p=0.003) but did not significantly change RPElegs +0.55 ± 0.2 units (p=0.46). We found that dyspnea during exercise is susceptible to expectancy, without any accompanying physiological changes. Given coaches and clinicians uses perceived exertion to prescribe exercise intensity and evaluate treatments, our finding show that the effect of expectations must be considered when interpreting sensations of breathlessness.
Published: 29 August 2022
Applied Physiology, Nutrition, and Metabolism; https://doi.org/10.1139/apnm-2022-0251
Sports nutrition for athletes with a spinal cord injury (SCI) is complex, making it challenging for athletes to stay informed. The aim of this study was to assess sports nutrition knowledge in athletes with a SCI and coaches of para sports. The secondary aim was to report sources of sports nutrition information. Eighty athletes and twenty-six coaches across various adapted sports were recruited. The Nutrition for Sport Knowledge Questionnaire was used to assess nutrition knowledge for both groups. Athletes achieved their highest score among the alcohol (65 ± 19%) category and the lowest in sports nutrition (43 ± 17%). Coaches demonstrated the most knowledge in the alcohol (73 ± 17%) category and lowest knowledge in the supplementation (45 ± 19%) category. Both groups relied on the internet, dietitians, and coaches for sports nutrition information. Future studies should explore the effects of nutrition education on nutrition knowledge and dietary intakes among these populations.