Metabolism, Sleep, and Obesity

Subject: Healthcare Research
Pages: 5
Words: 1082
Reading time:
4 min
Study level: Bachelor


Today, much attention is paid to the quality of sleep and its impact on various disorders and health problems. This presentation discusses the relationship between three issues: metabolism, sleep, and obesity. Sleep is connected to hormonal and metabolic changes, provoking imbalance and disruption of functions. As soon as metabolism is challenged in the body, new harms occur. For example, during sleep, metabolic flexibility may be a risk factor for obesity. In this paper, the study by Zhang et al. (2021) will be used to examine metabolic flexibility during sleep and its effect on obesity. In addition to obesity issues, metabolic activity, (in)flexibility, and sleep quality will be analyzed.

Sleep and Metabolism

Metabolism is a vital body process consisting of multiple chemical reactions to change food into energy. Food and beverages consumed by humans contain a number of calories and other substances combined with oxygen to promote daily activities and body adaptation. To better explain this process, researchers introduced the concept of metabolic flexibility as the ability of the body to respond/adapt in regard to conditional changes in metabolic demand (Goodpaster & Sparks, 2017; Zhang et al., 2021). It happens that flexibility is disrupted by low fasting fat oxidation or impaired abilities to oxidize substrates during sleep (Zhang et al., 2021). These problems are known as metabolic inflexibility because of poor sleep and uncontrolled fasting processes.

Obesity Issues

Metabolic inflexibility is a challenge for the body, and it is necessary to learn how to help the body control all processes during sleep. According to Zhang et al. (2021), poor metabolism is a reason for an increased likelihood of diabetes, insulin issues, and weight-related problems. Goodpaster and Sparks (2017) report metabolic inflexibility in the body challenged by type 2 diabetes and obesity. Obesity refers to supernormal fat accumulation that results from unhealthy eating behaviors. Another cause of obesity is related to elevated glucose oxidation in a post-absorptive period (Goodpaster & Sparks, 2017). Sleep quality also matters in understanding obesity risks and metabolic pathologies because this process contributes to fasting duration and energy exchange.

Metabolic Activity

Metabolic activity is the process in which the body can synthesize food products for energy. It refers to balancing the needs between various aspects of the body’s activities, including breaking down body tissues, fats, and acids. It revolves around the selection of fuel sources and the body’s functioning. Insulin resistance is characterized by a positive change in fatty acid oxidation and an accompanying decrease in glucose oxidation. It measures food and substances surrounding the metabolism, relating to the respiratory quotient, fuel selection techniques, and the extent of insulin resistance in the context of consideration of the body state during different times.

Metabolic Flexibility

Metabolic flexibility leads to an increase in energy demands to enable rigorous exercise practices. Muscle plasticity is the capability of muscle tissue to respond to the stimuli characteristics, especially metabolic flexibility. Significant changes occur due to changes in the exercise cycle. Several aspects should be met to balance the energy requirements and gain more insight into the finer details of the metabolic procedure (Zhang et al., 2021). In humans, the skeletal muscles and the tissues play a vital role in gaining a deep insight into metabolism (Goodpaster & Sparks, 2017). They have deep integration into body organization to prevent infections and health concerns.

Metabolic Inflexibility

Insulin resistance is a function that entails many factors to promote metabolic flexibility and be attributed to the incapacity of the components involved in the metabolism processes. There is a significant increase in glucose breakdown, which further points to increased incidences of insulin resistance. Resistance involves tissue and organ development and forms an integral aspect of metabolic flexibility. Glucose metabolism is a response to insulin that causes energy drains from the body, metabolic changes, and resistance to insulin rates. During sleep, there is more insulin resistance due to a reduction in the body’s energy needs, increasing the chances of developing chronic diseases like diabetes or obesity.

Metabolic Flexibility and Respiratory Quotient

Sleep is a period when the body gathers enough energy and compounds to respond to physiological threats and respond to the development of chronic illnesses with time. Behavioral changes are hard to predict, which causes increased fat and acid levels and inadequate oxidation. Zhang et al. (2021) offer to promote metabolic adaptability to shift from fuel oxidation to fuel availability. A respiratory quotient was offered to examine the relationship between carbon dioxide and oxygen absorption in the body (Zhang et al., 2021). Water procedures were conducted to measure energy levels in a free-living condition (Zhang et al., 2021). Being a fasting period, sleep is associated with decreased respiratory quotient and flexible metabolism, depending on personal needs.

Obesity Risk During Sleep

The discussion of insulin resistance and metabolic changes during sleep is critical for understanding the relationship between sleep and obesity. Zhang et al. (2021) prove that insufficient sleep will become a serious risk factor for obesity and weight management. Sleep restores neuroendocrine functioning and improves glucose metabolism for the body to have enough energy for daily activities. When the quality of sleep gets worsens, additional problems emerge, including decreased glucose tolerance (high insulin provokes new fats), poor insulin sensitivity (inability to recognize metabolic processes), and greater oxidation (oxidative stress activates harmful substances). As a result, glucose remains poorly managed in the body, and its storage provokes additional fat and the desire to eat more (Zhang et al., 2021). Finally, the body is not able to oxidate fat acid properly, and reduced oxidation means increased fat levels and obesity.

Metabolic Changes and Obesity

The relationship between human metabolism and obesity is evident. Physical activities and exercises aim at improving human metabolism and are also associated with weight management. When a person sleeps, no activities are made to control metabolism. Obese individuals remain resistant to insulin effects, which provokes challenges in glucose stimulation and increased fatty acids. As a result, additional health complications are reported because of increased fat mass, connecting insulin resistance, obesity, and metabolism.


In general, this paper proves the importance of high-quality sleep for the body. This process allows for regulating most metabolic processes and formulating effective eating habits. If metabolism is challenged, metabolic inflexibility is reported, provoking fat oxidation changes. Disrupted metabolic flexibility contributes to the development of diabetes, insulin problems, and obesity. In people with inflexible metabolism, less fat is burned during sleep, while flexible metabolism is associated with more fat being burned. Thus, metabolic flexibility is a potential indicator of obesity risk during sleep.


Goodpaster, B. H., & Sparks, L. M. (2017). Metabolic flexibility in health and disease. Cell Metabolism, 25(5), 1027-1036. Web.

Zhang, S., Tanaka, Y., Ishihara, A., Uchizawa, A., Park, I., Iwayama, K., Ogata, H., Yajima, K., Omi, N., Satoh, M., Yanagisawa, M., Sagayama, H., & Tokuyama, K. (2021). Metabolic flexibility during sleep. Scientific Reports, 11(1). Web.