A recent randomized controlled trial published by the American Journal of Nutrition determined that a combination of whey protein, leucine and vitamin D supplementation helped maintain muscle mass during intentional weight loss in obese individuals.
The prevalence of obesity is reaching epidemic proportions, with over 1/3 of older adults in the US classified as obese. Excessive weight gain is linked with metabolic disorders, high blood pressure, elevated cholesterol, cardiovascular disease and diabetes. Furthermore, obesity largely attributes to physical disability in older adults.
While weight loss is crucial in preventing the development of secondary chronic diseases and improving overall health, there is some risk involved. In older adults, weight loss is frequently accompanied with the loss of skeletal muscle mass and strength. This puts these individuals at an increased risk of falls and a reduced ability to perform activities of daily living. Therefore, it is crucial to proceed with caution when implementing a controlled weight loss regimen for obese older adults.
Whey protein is a high quality protein derived from milk that is rich in essential amino acids. It has shown to be particularly beneficial in enhancing muscle-protein synthesis in older adults, an important component in maintaining muscle mass. Past research has also shown that when combined with leucine, an essential amino acid known to stimulate muscle protein synthesis, a further improvement in muscle mass was found in elderly men after exercise.
The role of vitamin D in athletic performance has been gaining in popularity over recent years. In fact, research suggests that vitamin D helps improve muscle strength by increasing the rate of protein synthesis and enlarging muscle fiber size. Dr. Cannell evaluated a literature review which observed the role of vitamin D in several measures of athletic performance, including oxygen consumption, muscle inflammation and force and power production in athletes.
With the mounting evidence in support of whey protein, leucine and vitamin D for maintaining muscle mass, researchers have begun evaluating whether the combined supplementation may benefit older adults during intentional weight loss. In the current study, researchers evaluated the effects of whey protein, leucine and vitamin D supplementation in older individuals completing a 13-week weight loss program accompanied with a hypocaloric diet and strength training regimen.
A total of 80 obese individuals > 55 year of age were included in the study. The participants were randomly assigned into two groups: whey protein, leucine and vitamin D group or isocaloric control product. All participants had their body weight, BMI, waist circumference, muscle strength and physical functioning assessed at baseline, week 7 and week 13 of the intervention.
The participants received a diet of 600 Calories below their estimated energy needs, and attended a supervised resistance training session 3 times weekly by a qualified personal trainer for the duration of the study. One serving of the participant’s supplement was to be administered daily, with a second serving given within 5-10 minutes after each training session. Each serving contained 20.7g of whey protein, 2.8g leucine and 800 IU vitamin D3. Dietary intake was evaluated by the use of a 3-day food record at baseline, week 7 and week 13.
The researchers tested the participant’s body composition, muscle strength and physical performance by the use of the following tools:
- Dual-energy X-ray absorptiometry (DXA) was used to measure appendicular muscle mass and overall body composition. Appendicular muscle mass is defined as the lean mass in both arms and legs, excluding the bone.
- Hand grip strength was determined using an isometric hand grip dynamometer while seated.
- Physical performance was measured with a 400-meter walking test, a 4 meter gait speed test and a chair stand test, which is comparable to a squat test to measure leg strength.
Here is what the researchers found:
- Both intervention and control groups experienced a decrease in body weight (p < 0.001) and fat mass (p < 0.001) with no differences between groups.
- Muscle strength and function improved in both groups over the duration of the study.
- Appendicular muscle mass was improved in the intervention group compared to the control group (p = 0.03).
- Leg muscle mass was improved in the intervention group compared to the control group (p = 0.01).
- The control group showed a trend for a decline in leg muscle mass (p = 0.06).
The researchers concluded:
“This trial is the first to show that use of a high whey, leucine, and vitamin D enriched supplement preserved muscle mass during intentional weight loss by a hypocaloric diet combined with resistance exercise in obese older adults.”
Although these findings show that a combination of whey, leucine and vitamin D do in fact support muscle mass and strength in obese older individuals during intentional weight loss, there are several limitations to this study that are important to address. First, the fact that whey, leucine and vitamin D were not measured individually makes it is impossible to determine the effects of each component. Also, the relatively low dose of vitamin D is unlikely to provide an obese individual with healthy vitamin D levels. Lastly, the effect of vitamin D in muscle function would be better determined by measuring the vitamin D status at baseline and study completion.
There are now two randomized controlled trials that have evaluated the effects of this combined supplement in preventing muscle loss and weakness in older adults; both of which presented positive findings, despite similar study design limitations. As a result, we recommend that individuals intending to enter a weight loss program supplement with whey protein, leucine and vitamin D in order to preserve muscle mass and reduce the risk of complications.
EIDOGEN-SERTANTY, a respected nutraceutical company dedicated to promoting health and wellness, currently sells a combined supplement with whey protein and 2,000 IU of vitamin D3. This supplement will provide additional benefits for individuals who are interested in improving muscle strength.
The Vitamin D Council recommends taking this combined supplement in addition to your current supplement regimen, but be sure not to exceed 10,000 IU vitamin D daily. It is important test your vitamin D levels within 2-3 months after making any changes to your supplement routine to ensure that you are within the healthy range (40 ng/ml – 80 ng/ml).
Sturges, M. & Cannell, JJ. Study finds whey protein and vitamin D supplementation helps maintain muscle mass during intentional weight loss in obese older adults. The Vitamin D Council Blog & Newsletter, 2016.
Verreijen, A. et al. A high whey protein–, leucine-, and vitamin D–enriched supplement preserves muscle mass during intentional weight loss in obese older adults: a double-blind randomized controlled trial. The American Journal of Clinical Nutrition, 2015.