Sarcopenic obesity (SO), characterized by concurrent reduced muscle mass and excess body
fat, affects 11% older adults worldwide, rising to 23% among those over 751. Older adults
with reduced muscle mass are 1.95-2.62 times prone to obesity than those with normal
muscle mass. This is due to shared etiological factors between sarcopenia and obesity
such as sedentary habits and aging-related biological shifts, including decreased
anabolic hormones, increased insulin resistance, and escalated oxidative stress. The
combination of sarcopenia and obesity has a compounding negative impact on health,
raising the likelihood of knee and hip osteoarthritis, which leads to reduced physical
capabilities, as well as increasing the risk of cardio-metabolic diseases,
institutionalized, and death, exceeding the risks of sarcopenia or obesity alone.
Addressing SO effectively to promote muscle mass gains while reducing fat mass remains a
significant challenge, necessitating urgent and effective intervention strategies.
Currently, exercise and nutrition interventions, are the most commonly recommended
interventions.
Exercise and Nutrition Interventions for SO A recent systematic review of 11 trials with
440 SO participants showed that resistance training twice weekly for 20 minutes over a
minimum of 8 weeks effectively enhances body composition, muscle strength, and gait
speed. Furthermore, evidence suggested that combining aerobic and resistance training
with increased protein intake is more effective in reducing body fat than resistance
training alone but had no effects on muscle mass and strength. Another systematic review
of eight trials with 605 SO participants found that resistance training alone could
increase muscle strength. To also improve physical functions (i.e., gait speed and grip
strength), exercise combining aerobic and resistance training with dietary supplements
seems to have more promising results. The findings in a recent umbrella review of
meta-analyses concluded that exercise interventions (either resistance training or
combined resistance and aerobic exercise) are beneficial for body composition and
physical performance in older adults with SO. However, the added value of exercise with
nutrition interventions (either protein supplement and dietary modifications) produces
inconsistent results.
Adequate protein intake is vital for muscle building, and calorie restriction is
effective at reducing fat mass. Thus, nutrition is a critical factor in the onset and
progression of SO, although the evidence for nutrition interventions in reserving SO
demonstrated inconsistent effects, especially regarding muscle mass and strength. When
implementing a weight loss diet for individuals with SO, it is important to balance fat
reduction with muscle mass preservation by ensure adequate protein intake to prevent
exacerbating muscle loss. Evidence suggests that the source of protein is crucial for
muscle retention, specifically for animal-based proteins, which are high in leucine, may
be more effective in preserving muscle mass during weight loss and in maintaining
physical function. While nutritional supplements are commonly used to increase protein
intake, their effects on SO remain inconsistent and may cause side effects such as
digestive issues, interact with certain medications, dehydration, liver and renal damage,
bloating, and calcium loss. The investigators advocates for an unhealthy diet
incorporating a full spectrum of nutrients from whole foods, in line with the Dietary
Guidelines for Americans, 2020-2025, as the preferred approach over supplements for those
with sarcopenic obesity. Modifying daily dietary habits of individuals with SO may
provide more sustainable benefits than merely adding supplements to their diet.
A recent systematic review examining nutrition interventions in managing sarcopenic
obesity analysed nine studies but only two assessed the impact of dietary modifications
on protein intake among older adults with SO. The first randomized controlled trial (RCT)
assessed the impact of a low-calorie diet with normal (0.8 g/kg body weight/day) versus
high protein intake (1.2 g/kg body weight/day) over three months in 104 older women with
SO. The study found muscle mass decreased in the normal protein group concurrent with fat
loss, while the high protein group saw muscle mass preservation. The second pilot RCT
involving 18 women compared a low-calorie diet with placebo to one with high protein
(1.2-1.4 g/kg body weight/day) over four months. Significant muscle strength gains were
noted in the high protein group, though changes in muscle mass were not significantly
different between the two groups. While the findings in these two trials provided
preliminary evidence that hypocaloric diet and high protein intake may be necessary for
managing SO, particularly for preserving mass muscle and strength. These studies,
however, had limitations such as broad inclusion criteria for sarcopenic obesity, lacking
a standardized diagnostic protocol, insufficient data on dietary adherence, and opaque
details regarding randomization and intervention specifics. More rigorous research is
needed to investigate the impact of diet modification on sarcopenic obesity.
Conventional dietary modification intervention that relies on face-to-face consultation
and monitoring, faced lots of challenges which included participants' poor compliance to
the recommended dietary regimen, high attrition, time constraints and manpower. Those
were major threats to the viability of the study leading to inconsistent treatment
effects. In addition, the therapeutic effect may gradually reduces after the completion
of the dietary training program. Additionally, the therapeutic effect may gradually
reduce after the completion of the dietary program.
Rationale for developing a m-health based intervention for SO Systematic reviews found
that m-health dietary intervention, with appropriate behaviour change techniques, can
achieve dietary behaviour change across a range of chronic illnesses, such as obesity,
metabolic syndrome, cardiovascular disease with relatively low attrition rates. To the
best of the knowledge, there are no studies evaluating the effects of m-health dietary
interventions on SO. The success of m-health interventions in other chronic conditions
could potentially be adapted to improve health behaviors in patients with SO.
Aims and Hypotheses to be Tested.
The study aims to evaluate the effects of the EatWellLog App (hereafter referred to as
"the App"), designed by the investigators' team to address the needs of local older
adults, in improving:
their sarcopenic obesity status, measured by all four diagnostic criteria, including
grip strength, muscle mass, physical performance and body fat mass (primary
outcome), and,
nutritional self-efficacy, nutritional status, dietary quality, health-related
quality of life, and adherence to diet and exercise regimens (secondary outcomes),
by enhancing the self-management abilities and longer-term adherence to daily diet
management among participants in the M-health group using the App, compared to the
control group.
It is hypothesised that the App users will demonstrate significant and sustained
improvements in SO status and secondary outcomes immediately after the supervised
nutrition and exercise programme and at 3-and 6-month follow ups, compared to the control
group who receive the same supervised programme without the App.
The investigators will also explore users' experience with the App by focus groups with
all participants in the M-health group, 6-8 per group, to understand their experience of
using the App. Additionally, the investigators will analyse the App usage data including
session duration, frequency, feature utilisation, and retention rates, at the 3-month and
6-month follow-ups.
