BackgroundIncreased physical activity and dietary protein intake are promising interventions to prevent or treat the age-related decline in physical performance in older adults. There are well-controlled exercise as well as dietary intervention studies that show beneficial effects on physical performance in older adults. In practice, however, weekly group based exercise or nutritional programs may not be as effective. To optimise these exercise programs for community dwelling older adults, a digitally supported and personalised home-based exercise training program has been designed aiming to improve physical performance in older adults. In addition, a protein intervention in combination with the training program may further improve physical performance in older adults.MethodsThe VITAMIN study will be a cluster randomised controlled trial with three parallel arms. In total, 240 community dwelling older adults (≥ 55 years) participating in weekly group exercise are randomly allocated into: 1) regular weekly exercise program (Control group, n = 80), 2) digitally supported personalised home-based exercise training program group (VITA group, n = 80) and 3) digitally supported personalised home-based exercise training program group plus dietary protein counselling (VITA-Pro group, n = 80). The VITAMIN study aims to evaluate effectiveness of the digitally supported personalised home-based exercise training program as well as the additional value of dietary protein on physical performance after 6 months. In addition, a 12 month follow-up measurement will assess the retaining effect of the interventions. Primary outcome is physical performance measured by the Modified Physical Performance Test (M-PPT) and relevant secondary and observational outcomes include habitual physical activity and dietary intake, body composition, cognitive performance, quality of life, compliance and tablet usage. Data will be analysed by Linear Mixed Models.DiscussionTo our knowledge, the VITAMIN study is the first study that investigates the impact of home-based exercise, protein intake as well as use of persuasive technology in the population of community dwelling older adults.Trial registrationNL56094.029.16 / NTR (TC = 5888; registered 03–06-2016).
Background: A higher protein intake is suggested to preserve muscle mass during aging and may therefore reduce the risk of sarcopenia.Objectives: We explored whether the amount and type (animal or vegetable) of protein intake were associated with 5-y change in mid-thigh muscle cross-sectional area (CSA) in older adults (n = 1561).Methods: Protein intake was assessed at year 2 by a Block foodfrequency questionnaire in participants (aged 70–79 y) of the Health, Aging, and Body Composition (Health ABC) Study, a prospective cohort study. At year 1 and year 6 mid-thigh muscle CSA in square centimeters was measured by computed tomography. Multiple linearregression analysis was used to examine the association between energy-adjusted protein residuals in grams per day (total, animal, and vegetable protein) and muscle CSA at year 6, adjusted for muscle CSA at year 1 and potential confounders including prevalent health conditions, physical activity, and 5-y change in fat mass.Results: Mean (95% CI) protein intake was 0.90 (0.88, 0.92) g ·kg–1 · d–1 and mean (95% CI) 5-y change in muscle CSA was −9.8 (−10.6, −8.9) cm2. No association was observed between energyadjusted total (β = −0.00; 95% CI: −0.06, 0.06 cm2; P = 0.982), animal (β = −0.00; 95% CI: −0.06, 0.05 cm2; P = 0.923), or plant(β = +0.07; 95% CI: −0.06, 0.21 cm2; P = 0.276) protein intake and muscle CSA at year 6, adjusted for baseline mid-thigh muscle CSA and potential confounders.Conclusions: This study suggests that a higher total, animal, or vegetable protein intake is not associated with 5-y change in midthigh muscle CSA in older adults. This conclusion contradicts some, but not all, previous research. This trial was registered at www.trialregister.nl as NTR6930.
Introduction: A protein intake of 25–30 g per meal is suggested to maximally stimulate muscle protein synthesis in older adults in order to prevent sarcopenia. Protein intake at breakfast is often low and therefore breakfast offers the potential for protein suppletion. Since protein is known for its satiating effects, we explored the association between the amount of protein intake at breakfast and total daily protein intake in older adults. Methods: Baseline protein intake was assessed by a 3-day dietary record in 507 community dwelling older adults of 55 years and older participating in lifestyle interventions at the Amsterdam Nutritional Assessment Center. Multiple linear regression analysis was used to examine the association between protein intake at breakfast (in g) and total daily protein intake (in g, and g/kg body weight), adjusted for energy intake (kcal/d), sex, age and BMI. Interactions were tested for sex, age and BMI but were not significant (p>0.80). Results: Mean age was 67.6 ± (SD) 7.3 years, 42% was female, and mean BMI was 30.0 ± 5.6 kg/m2. Total daily protein intake was 81 ± 24 g which equals 0.96 ± 0.3 g/kg and 17.6 ± 3.7 percent of total energy intake. Protein intake at breakfast was 14 ± 7 g. A 10 g higher protein intake at breakfast was associated with a 6.7 g (SE = 1.0; P<0.001) and a 0.06 g/kg (SE = 0.01; P<0.001) higher total daily protein intake after adjustment for confounders. Key conclusions: A higher protein intake at breakfast does not compromise total daily protein intake in community dwelling older adults.
While the creation of an energy deficit (ED) is required for weight loss, it is well documented that actual weight loss is generally lower than what expected based on the initially imposed ED, a result of adaptive mechanisms that are oppose to initial ED to result in energy balance at a lower set-point. In addition to leading to plateauing weight loss, these adaptive responses have also been implicated in weight regain and weight cycling (add consequences). Adaptions occur both on the intake side, leading to a hyperphagic state in which food intake is favored (elevated levels of hunger, appetite, cravings etc.), as well as on the expenditure side, as adaptive thermogenesis reduces energy expenditure through compensatory reductions in resting metabolic rate (RMR), non-exercise activity expenditure (NEAT) and the thermic effect of food (TEF). Two strategies that have been utilized to improve weight loss outcomes include increasing dietary protein content and increasing energy flux during weight loss. Preliminary data from our group and others demonstrate that both approaches - especially when combined - have the capacity to reduce the hyperphagic response and attenuate reductions in energy expenditure, thereby minimizing the adaptive mechanisms implicated in plateauing weight loss, weight regain and weight cycling. Past research has largely focused on one specific component of energy balance (e.g. hunger or RMR) rather than assessing the impact of these strategies on all components of energy balance. Given that all components of energy balance are strongly connected with each other and therefore can potentially negate beneficial impacts on one specific component, the primary objective of this application is to use a comprehensive approach that integrates all components of energy balance to quantify the changes in response to a high protein and high energy flux, alone and in combination, during weight loss (Fig 1). Our central hypothesis is that a combination of high protein intake and high energy flux will be most effective at minimizing both metabolic and behavioral adaptations in several components of energy balance such that the hyperphagic state and adaptive thermogenesis are attenuated to lead to superior weight loss results and long-term weight maintenance.
