What Is the Main Idea?
In old age, with muscle mass loss and increased weight gain, there are increased health risks like falling, fracturing, and being susceptible to other diseases. Due to gender and age-related hormonal changes, this is especially true for postmenopausal women. In the open access review article with the rather long title “Impact of Protein Intake during Weight Loss on Preservation of Fat-Free Mass, Resting Energy Expenditure, and Physical Function in Overweight Postmenopausal Women: A Randomized Controlled Trial”, published in the journal Obesity Facts, the authors find that high protein alone doesn’t significantly help in improving muscle mass during weight reduction.
What Else Can You Learn?
Sarcopenia obesity is a condition that encompasses all these problems. Learn more about this, the causes, and the interventions for this.
What Is Sarcopenia?
Sarcopenia, a condition of loss of muscle mass and physical function due to old age, is derived from two Greek words – “sarx” which means “flesh” and “penia” which means “loss”. Starting with 1–2% loss at 30 years, by the time one reaches 80 years, those affected can lose up to 30% of their muscle mass. Since we are talking about muscles, loss of this mass leads to loss of strength. This makes old people weaker, less mobile and functional, and more susceptible to falls and fractures. Overall, it results in a poor quality of life.
What Does Obesity Have to Do with Sarcopenia?
In some people, the loss of muscle mass happens along with an increase in the fat (adipose) tissue. This shift in the composition of the body can slowly lead to a combined situation which is called sarcopenia obesity. The duality of these problems leads to making all effects of sarcopenia worse and further increases the risk of comorbidities like osteoarthritis, type 2 diabetes, and even depression. Unfortunately, the condition has not yet been well defined but with an aging population and a rise in obesity, there is more research being done to understand sarcopenia obesity.
From what we currently know, what are the potential factors that cause sarcopenia obesity? Age-related changes in body composition, less physical activity, and hormonal changes are some factors that lead to this condition. At the molecular level too, as we age, certain inflammatory pathways, reduced ability to detoxify and changes in the muscle composition can further worsen sarcopenia obesity.
Why Should Postmenopausal Women Care about This Condition?
With changes in body composition, postmenopausal women are already more susceptible to being obese. In the USA, 40% of women aged 65–74 years were obese, and in Germany, 61% of women aged 50–59 years were overweight, with 27% being obese. In addition, the lower estrogen levels in postmenopause can lead to inflammatory responses that damage skeletal muscle. On the other hand, the presence of estrogen can stimulate cell proliferation. In fact, in a study in Korea, the authors found that the use of hormone therapy in postmenopausal women for 13 months or more helped in increasing muscle mass and reducing sarcopenia. Since hormone therapy has other effects, more studies have to be conducted to make it a definitive treatment for sarcopenia obesity in postmenopausal women.
Meanwhile, let us look into interventions for sarcopenia obesity in general and what can be adapted for postmenopausal women.
How Is This Condition Treated?
While there are emerging novel therapies targeting muscle function, weight loss, and hormonal therapies, the primary strategies currently are still related to physical activity or dietary changes. For each therapy, there are many things to consider like the age of the individual, the gender, and the current physical ability. Some studies showed that to improve physical function, the combination of the physical activity with a weight loss intervention was more effective than doing any one separately.
When it comes to helping overcome sarcopenia obesity, the interventions of weight loss are an important treatment strategy. However, it is important to consider that along with weight loss, loss of muscle mass (part of fat-free mass) can occur which can make sarcopenia worse. Since the energy spent at rest is directly related to the fat-free mass, with lower fat-free mass, this energy spent will go down. Therefore, an important intervention is increasing protein intake during weight loss regimens. This is one of the dietary changes recommended. Moreover, the authors of a study found that increasing protein intake can help improve physical function even without physical exercise.
Does a High-Protein Diet for Postmenopausal Overweight Women Work?
To understand the impact of a high-protein diet in postmenopausal overweight women, the authors of the above-mentioned open access paper conducted a study in Germany with 54 women in this category. Half of them were given a high-protein (1.5 g protein/kg weight) and the other half were given a normal-protein (0.8 g protein/kg weight) diet for a period of 12 weeks and then were monitored for 6 months. There was significant weight loss in both groups, including in the follow-up.
Surprisingly, however, there was no significant difference in net weight loss or the fat-free mass loss between the 2 groups. So, the high-protein diet did not really help in preserving the fat-free mass. The only significant difference between the 2 groups was that higher protein intake helped in improving physical function, as in the earlier study. The authors concluded that compared to a normal-protein diet, a high-protein diet without any physical exercise does not help the postmenopausal overweight women preserve their muscle mass during weight loss.
So, How Does This Matter to a Postmenopausal Obese Woman?
With an increased risk of sarcopenia obesity, this group should look for a holistic treatment of physical exercise and nutrition changes. They should talk to their doctor or nutritionist about creating a program for them. When it comes to physical exercise, they should consider including both aerobic exercise and resistance training. For nutrition changes, along with high-protein, low-calorie diet, they should consider vitamin D and calcium supplements.