Why does our Resting Metabolism Slow Down as we Age?

As we age, several factors contribute to the loss of muscle mass, a condition known as sarcopenia:

Hormonal changes: Aging is associated with changes in hormone levels, including a decline in anabolic hormones such as growth hormone, testosterone (in men), and estrogen (in women). These hormones play crucial roles in muscle protein synthesis and maintenance. Decreased hormone levels can lead to a reduction in muscle mass and strength over time.
Decreased physical activity: Older adults tend to be less physically active than younger individuals due to factors such as decreased mobility, chronic health conditions, and lifestyle changes. Reduced physical activity levels contribute to muscle disuse and atrophy, leading to a loss of muscle mass and strength.
Impaired protein metabolism: Aging is associated with alterations in protein metabolism, including decreased protein synthesis and increased protein breakdown. This imbalance in protein turnover contributes to muscle loss and may be exacerbated by factors such as inadequate protein intake and chronic inflammation.
Neuromuscular changes: Age-related changes in the nervous system and neuromuscular junctions can impair motor unit recruitment and muscle activation. These changes result in decreased muscle force production and may contribute to muscle weakness and atrophy.
Nutritional factors: Poor nutrition, including inadequate protein intake and micronutrient deficiencies, can contribute to muscle loss and sarcopenia. Older adults may also experience decreased appetite, changes in taste and smell, and difficulty chewing or swallowing, which can affect nutritional status and muscle health.

The loss of muscle mass with aging has significant implications for resting metabolism:

Decreased basal metabolic rate (BMR): Muscle tissue is metabolically active and requires energy for maintenance, even at rest. As muscle mass declines, basal metabolic rate decreases because there is less metabolically active tissue requiring energy. This reduction in BMR can contribute to a decrease in overall resting metabolic rate (RMR).
Impaired glucose metabolism: Skeletal muscle plays a critical role in glucose metabolism, as it is the primary site for insulin-mediated glucose uptake and utilization. Loss of muscle mass and insulin resistance commonly observed with aging can impair glucose disposal and contribute to metabolic dysregulation, including an increased risk of type 2 diabetes.
Reduced physical function: Muscle loss and weakness can impair physical function, mobility, and balance, leading to decreased physical activity levels and further exacerbating declines in metabolic rate and overall health.

To mitigate age-related muscle loss and its impact on resting metabolism, it’s important to engage in regular resistance training exercises to preserve and build muscle mass, consume an adequate protein-rich diet, and maintain overall physical activity levels. Additionally, addressing other factors such as hormonal imbalances, nutritional deficiencies, and chronic inflammation can help support muscle health and metabolic function as we age.

If you want to improve your BAT to improve your resting metabolism… what else can you do besides cold plunges??

Besides cold thermogenesis, there are several other ways to potentially improve brown adipose tissue (BAT) activity:

Exercise: Regular physical activity, especially high-intensity interval training (HIIT), has been shown to increase BAT activity. HIIT can stimulate the production of irisin, a hormone that can convert white fat cells into brown fat cells, thereby increasing BAT activity.
Dietary factors: Certain dietary factors may influence BAT activity. For example, consuming capsaicin, found in spicy foods like chili peppers, has been shown to increase BAT activity. Additionally, some research suggests that certain nutrients like omega-3 fatty acids and polyphenols found in foods like fish, nuts, seeds, and berries may also enhance BAT function.
Sleep: Getting adequate sleep is important for overall metabolic health, including BAT function. Poor sleep quality or insufficient sleep has been linked to decreased BAT activity and increased white fat accumulation.
Sunlight exposure: Limited evidence suggests that exposure to natural sunlight or bright light therapy may increase BAT activity. Sunlight exposure helps regulate circadian rhythms, which in turn can affect metabolic processes including BAT activity.
Intermittent fasting: Some studies suggest that intermittent fasting, which involves cycling between periods of eating and fasting, may increase BAT activity. However, more research is needed to fully understand the effects of intermittent fasting on BAT function.
Thyroid hormones: Thyroid hormones play a key role in regulating metabolism, including BAT activity. Ensuring optimal thyroid function through proper nutrition and medical management, if necessary, may support healthy BAT activity.
Cold exposure mimetics: Certain compounds or drugs that mimic the effects of cold exposure without actually requiring cold exposure are being investigated for their potential to increase BAT activity. These compounds may work by activating the same pathways as cold exposure, such as activating the sympathetic nervous system.
Brown adipose tissue activation agents: Research is ongoing to identify compounds or drugs that directly stimulate BAT activity. These agents may target specific receptors or signaling pathways involved in BAT activation and could potentially be used as treatments for obesity and metabolic disorders.

It’s important to note that while these strategies may potentially enhance BAT activity, individual responses can vary, and more research is needed to fully understand their effectiveness and safety. Additionally, it’s always a good idea to consult with a healthcare professional before making significant changes to your lifestyle or starting any new supplements or medications.

What is the difference of White, Beige and Brown Adipose Tissue?

Beige fat, also known as brite (brown-in-white) or inducible brown fat, is a type of fat tissue that shares characteristics with both white adipose tissue (WAT) and brown adipose tissue (BAT). While white fat primarily stores energy in the form of triglycerides and brown fat is specialized for energy expenditure and thermogenesis, beige fat has the ability to exhibit brown fat-like characteristics under certain conditions.

The primary distinguishing feature of beige fat is its capacity to undergo a process called “browning” or “beiging.” This involves the transformation of white fat cells into beige fat cells, which then acquire the ability to dissipate energy in the form of heat, similar to brown fat. This process is often stimulated by various environmental and physiological factors, such as cold exposure or certain hormones.

Key features of beige fat include:

Thermogenic capacity: Like brown fat, beige fat cells contain a high number of mitochondria and express the uncoupling protein 1 (UCP1), which is responsible for uncoupling oxidative phosphorylation from ATP synthesis. This uncoupling leads to the generation of heat.
Origins: Beige fat cells can arise from the “browning” of white fat cells or from a distinct lineage of precursor cells. The exact origin may depend on the specific depot of adipose tissue and the signaling pathways involved.
Stimuli for activation: Beige fat is often induced in response to certain stimuli, such as chronic cold exposure, exercise, or hormonal signals. For example, sympathetic nervous system activation and the release of norepinephrine can trigger the browning process.
Location: Beige fat depots are typically found interspersed within white fat depots. Unlike brown fat, which is concentrated in specific regions (e.g., the neck and upper back in humans), beige fat can be distributed throughout various white fat depots.

The discovery of beige fat has generated interest in its potential role in energy metabolism and its implications for combating obesity and metabolic disorders. Strategies to promote the browning of white fat, such as cold exposure or pharmacological interventions, are being investigated as potential approaches to enhance energy expenditure and improve metabolic health.

How do our genetics influence our Resting Metabolism?

Genetic variations, including single nucleotide polymorphisms (SNPs), can indeed influence various aspects of metabolism, including the conversion of white fat to brown fat. However, our understanding of the specific SNPs that impact this process is still evolving, and research in this area is ongoing. Here are a few examples of genes and SNPs that have been implicated in brown fat metabolism:

UCP1 gene: The uncoupling protein 1 (UCP1) gene is a key regulator of brown fat activity. Variations in the UCP1 gene have been associated with differences in brown fat thermogenesis and energy expenditure. Certain SNPs within the UCP1 gene may affect the expression or function of UCP1 protein, influencing the effectiveness of brown fat in converting white fat and increasing resting metabolism.
FTO gene: The fat mass and obesity-associated (FTO) gene is known to be associated with obesity risk and body mass index (BMI). Some studies have suggested that certain variants of the FTO gene may influence brown fat activity and thermogenesis. Variations in this gene could potentially impact the effectiveness of converting white fat to brown fat and its effects on resting metabolism.
PPARG gene: The peroxisome proliferator-activated receptor gamma (PPARG) gene is involved in the regulation of adipocyte differentiation and function, including brown fat development and metabolism. Variants in the PPARG gene have been linked to differences in adipose tissue distribution and metabolic traits. Certain SNPs within the PPARG gene may affect brown fat activity and its ability to improve resting metabolism.
ADIPOQ gene: The adiponectin (ADIPOQ) gene encodes a hormone involved in regulating glucose and lipid metabolism. Variants in the ADIPOQ gene have been associated with obesity, insulin resistance, and metabolic syndrome. While most research on ADIPOQ has focused on its effects on white adipose tissue, there is emerging evidence suggesting its potential role in brown fat metabolism and thermogenesis.
Other genes: Several other genes involved in various aspects of adipocyte biology, energy metabolism, and thermogenesis may also harbor SNPs that influence brown fat activity and resting metabolism. Examples include genes related to beta-adrenergic signaling, insulin signaling, and lipid metabolism.

It’s important to note that the impact of genetic variations on brown fat metabolism is likely to be complex and multifactorial, involving interactions between multiple genes and environmental factors. Additionally, the specific SNPs and their effects may vary across populations and individuals. Further research is needed to fully elucidate the genetic determinants of brown fat function and their implications for metabolism and metabolic health.

What else can we do to improve our Resting Metabolism as we age?

Improving resting metabolic rate (RMR) involves strategies that increase the body’s energy expenditure while at rest. Here are some effective ways to enhance RMR:

Increase lean muscle mass: Muscle tissue is metabolically active, meaning it burns more calories at rest compared to fat tissue. Engaging in resistance training exercises, such as weightlifting or bodyweight exercises, can help build and maintain lean muscle mass, thereby increasing RMR over time.
Stay active throughout the day: Incorporating physical activity into your daily routine can help boost RMR. This includes activities like walking, standing, and even fidgeting, which can contribute to non-exercise activity thermogenesis (NEAT) and increase calorie expenditure.
Eat enough protein: Consuming an adequate amount of protein is important for muscle maintenance and repair, which in turn can support a higher RMR. Protein also has a higher thermic effect of food compared to carbohydrates or fats, meaning it requires more energy to digest and metabolize.
Stay hydrated: Drinking enough water is essential for maintaining metabolic processes in the body, including those involved in energy metabolism. Dehydration can potentially decrease RMR, so it’s important to stay hydrated throughout the day.
Get enough sleep: Quality sleep is crucial for overall metabolic health, including RMR regulation. Poor sleep quality or insufficient sleep can disrupt hormone levels involved in appetite regulation and energy balance, potentially leading to a decrease in RMR over time.
Manage stress: Chronic stress can elevate levels of cortisol, a hormone that may contribute to metabolic dysfunction and decreased RMR. Practicing stress-reduction techniques such as mindfulness meditation, deep breathing exercises, or engaging in relaxing activities can help mitigate the negative effects of stress on metabolism.
Eat spicy foods: Spicy foods containing compounds like capsaicin have been shown to temporarily increase metabolism and energy expenditure. While the effect may be modest, incorporating spicy foods into your diet could potentially boost RMR slightly.
Consider caffeine and green tea: Caffeine and catechins found in green tea have been shown to modestly increase metabolism and fat oxidation. Consuming moderate amounts of caffeine or green tea may provide a slight boost to RMR, though it’s important to monitor intake to avoid negative effects such as jitteriness or disrupted sleep.
Ensure adequate micronutrient intake: Certain vitamins and minerals, such as vitamin D, iron, and magnesium, play important roles in metabolic processes and energy production. Ensuring adequate intake of these micronutrients through a balanced diet or supplementation may support optimal RMR.
Consult a healthcare professional: If you’re struggling with maintaining or increasing your RMR despite lifestyle modifications, it may be helpful to consult with a healthcare professional, such as a registered dietitian or endocrinologist. They can assess your individual needs and provide personalized recommendations based on your health status and goals.

How does our metabolic health and muscle health impact our RMR as we age?

As we age, several changes occur in metabolic health and muscle health that can influence metabolism:

Loss of lean muscle mass: With advancing age, there is a natural decline in muscle mass and strength, a phenomenon known as sarcopenia. This loss of lean muscle mass reduces basal metabolic rate (BMR) because muscle tissue is more metabolically active than fat tissue. As a result, older adults may experience a decrease in resting metabolic rate (RMR), making it more challenging to maintain or lose weight.
Decreased physical activity: Older adults often become less physically active over time due to factors such as mobility limitations, chronic health conditions, and lifestyle changes. Reduced physical activity levels can contribute to a decline in overall energy expenditure and metabolic rate, further exacerbating age-related changes in metabolism.
Changes in hormone levels: Hormonal changes associated with aging, such as declining levels of growth hormone, testosterone (in men), and estrogen (in women), can impact metabolism. These hormonal changes can influence muscle mass, fat distribution, and metabolic rate, potentially contributing to weight gain and metabolic dysregulation.
Impaired glucose metabolism and insulin sensitivity: Aging is associated with a gradual decline in glucose tolerance and insulin sensitivity, leading to an increased risk of insulin resistance, prediabetes, and type 2 diabetes. Impaired glucose metabolism can affect energy metabolism and contribute to alterations in resting metabolism.

To improve resting metabolism as we age, several strategies can be beneficial:

Strength training: Engaging in regular resistance training exercises can help preserve and build lean muscle mass, which is essential for maintaining a healthy metabolism. Strength training exercises should focus on major muscle groups and be performed at least two to three times per week.
Regular physical activity: Staying active is important for overall metabolic health and can help offset age-related declines in metabolism. Incorporating aerobic exercise, such as walking, swimming, or cycling, along with strength training, can support weight management and metabolic function.
Balanced diet: Consuming a balanced diet rich in lean protein, whole grains, fruits, vegetables, and healthy fats can provide essential nutrients for muscle health and metabolic function. Adequate protein intake is particularly important for older adults to support muscle maintenance and repair.
Manage stress: Chronic stress can negatively impact metabolism, so finding ways to manage stress through relaxation techniques, mindfulness practices, and social support can be beneficial for metabolic health.
Optimize sleep: Getting enough high-quality sleep is essential for metabolic health and overall well-being. Aim for seven to nine hours of sleep per night and practice good sleep hygiene habits to promote restorative sleep.

PNOE is a metabolic assessment system that uses indirect calorimetry to measure an individual’s metabolic rate and substrate utilization in real-time. By analyzing respiratory gases during rest and exercise, PNOE provides insights into an individual’s metabolic efficiency, energy expenditure, and fitness level.

Based on the metabolic data collected, PNOE can generate personalized recommendations for nutrition, exercise, and lifestyle modifications to optimize metabolic health and improve resting metabolism. These recommendations may include adjustments to macronutrient intake, exercise intensity and duration, and other lifestyle factors tailored to the individual’s metabolic profile and goals.

What if you don’t want to do daily cold plunges?