Kendra Lee

May 18, 2015

Kin 414

Dr. Brilla

Metabolic Balance Analysis

Upon completing my diet analysis using Nutritionist Pro, I learned that on average, I

consumed approximately 2,220 kilocalories. I then entered my activity information into a

formula using METS, time and weight to calculate the energy expenditure for everything I did,

including sleep. I burned about 2,618 kilocalories for the first day; the next two days were very

similar. Clearly there is an unbalance energy consumed and energy expended, which is common

to many people. Individuals believe that in order to lose weight, they must burn more calories

than they take in, but there are other variables that come into play too.

Obesity is a widespread health condition in the United States and increasing around the

world (Laposky, 2008). Obesity is a result of an increase in the total number and size of

adipocytes (Jequier, 2002). The Center for Disease Control and Prevention has stated that

obesity in adults has almost doubled, and nearly tripled in children and adolescents since the

1980’s (Laposky, 2008). Over 1.4 billion adults, 150 million school-aged children and 43 million

preschool children are overweight or obese worldwide (Markwald, 2013). Obesity raises the risk

of cardiovascular disease, hyperlipidemia, diabetes, osteoarthritis, sleep apnea, depression, and

cancer (Markwald, 2013). There are multitudes of studies that have been completed on how to

lose weight, and many of them focus on expending more kilocalories than they take in. There

are many various reasons why this doesn’t work the way it sounds. There are many factors in a

person’s life that may affect why they eat less kilocalories and do not lose weight, they may

even gain some.

A widely known trend that has emerged in the last couple decades show a steady

increase in overweight and obese individuals, as well an average decrease in hours of sleep per

night, referred to as the chronic sleep debt (Laposky, 2008). The daily sleep by American adults

has decreased approximately one to two hours per night, and adolescents showed even more

sleep deprivation since the 1980’s (Laposky, 2008). More than 30% of adults between the ages

of 30 and 64 sleep less than six hours per night (Knutson, 2007). Sleep deprivation can increase

appetite, decrease leptin and increase ghrelin levels (Laposky). It can also cause symptoms that

interfere with memory, mental cognition and emotional mood (Bosy-Westphal, 2008). Sleep

influences energy metabolism; one main function of sleep is to conserve energy (Markwald,

2013).

A Nurses’ Health Study looked at women who slept for less than five hours a night as

well as woman who slept more than eight hours. The lower sleep had a correlation with higher

body weight, and the more sleep correlated with the lowest body weight (Benedict, 2011). A

study conducted by Van Cauter and colleagues restricted healthy male subjects to four hours of

sleep for six nights. Elevated glucose levels, decreased insulin sensitivity following breakfast,

and decreased rate of glucose disposal were all seen (Laposky, 2008). A second study by the

same people for only two days with four hours of sleep resulted in reduced levels of leptin as

well as increased ghrelin levels and appetite (Laposky, 2008).

Sleep loss could also have an enormous effect on energy expenditure in relation to

leptin and ghrelin levels (Knutson, 2007). Research conducted on 14 young women who had

varied amounts of sleep, with the minimum being four hours a night, resulted in a 24%

decrease in leptin levels following the sleep loss. Leptin is inhibited by the Sympathetic Nervous

System (SNS), meaning sleep loss could hinder the SNS (Body-Westphal, 2008). It is a hormone

that is secreted by fat cells and is involved in the maintenance of energy stores (Jequier, 2002).

Leptin performs through the hypothalamic receptors to increase thermogenesis which results in

a reduction of body weight (Jequier, 2002). Leptin works in a negative feedback loop; it starts

by monitoring the energy store levels, then hypothalamic center receives and integrates the

leptin intensity, and lastly, the effector system determines the energy balance, including the

intake and expenditure (Jequier, 2002). This loop helps to maintain a constant body weight. If

an increase in weight occurs, then leptin levels increase to assist to cease the weight gain.

When weight loss occurs, leptin levels decrease because it doesn’t want the body to lose any

more weight to stay near homoeostasis (Jequier, 2002). Leptin secretion is related to the

circadian sleep rhythm and is not associated to meal intake, so it cannot be a controller of meal

size (Jequier, 2002).

Leptin arose during the evolution to assist in starvation when food was limited (Jequier,

2002). Fasting lessens leptin levels to ensure excessive weight loss does not follow (Jequier,

2002). Fasting over many days brought a decrease in body weight of 10% and a 53% reduction

in leptin levels (Jequier, 2002). Fasting also lessens leptin to ensure excessive weight loss does

not transpire (Jequier, 2002). This means that a decrease in energy consumption induced a

large decline in leptin secretion. During a fast or slow energy consumption, the body also

conserves energy by decreasing thyroid hormone, meaning a lower level of energy expenditure.

Fasting also lessens leptin levels to ensure excessive weight loss does not follow (Jequier, 2002).

That being said, if someone was to significantly reduce their caloric intake and want to expend

more calories, it would be difficult because the body would be conserving as much of this

energy as possible.

Another laboratory study of healthy men were subjected to four hours of sleep for six

nights followed by six nights of 12 hours of recovery sleep per night. It resulted in decreased

leptins level by 19% (Knutson, 2007). The maximum leptin levels differed by 1.7ng/ml on

average between the sleep debt and rested periods (Knutson, 2007). This is larger than the

decrease reported in young adults after a dietary restriction of about 900 kilocalories per day

(Knutson, 2007). Next to that, The Clinical Translational Research Center (CTRC) at the

University of Colorado Hospital researched 16 healthy subjects, eight were female and the rest

were male. Half of the participants slept five hours per night for five consecutive days, and the

other half slept nine hours per night for five days. They then switched so each person had the

opportunity to have a sleep debt and an adequate amount of sleep. The average leptin levels

increased by 22% in the five hours per night group, and did not significantly change in the nine

hours per night group (Markwald, 2013).

A separate male study that was restricted to four hours a night for two days resulted in

increased ghrelin concentrations especially in early morning (Benedict, 2011). Ghrelin is mostly

produced in the stomach and causes reduced energy expenditure and promotes fat storage

(Benedict, 2011). Ghrelin has the opposite effect of leptin on appetite and on energy

expenditure (Knutson, 2007). The same study as above which looked at 12 healthy young men

reported a 28% increase in ghrelin levels following the four hour bedtimes over a two day

period (Knutson, 2007). The study previously mentioned conducted by the CTRC also resulted in

a significant decrease in ghrelin levels. It reduced by approximately 30%, from 794.6 ±233.8

pg/mL at baseline, to 660.2 ±235.4 pg/mL during the five hours of sleep per night (Markwald,

2013).

Sleep deprivation also disturbs glucose metabolism (Body-Westphal, 2008). Chronic

sleep imitates the metabolic effects by activating the SNS and the sympatho-adreno-medullary

system which is part of the metabolic reaction to carbohydrate influence (Body-Westphal,

2008). Glucose tolerance refers to the ability to metabolize glucose and return to the baseline

levels (Knutson, 2007). It is reliant on the equilibrium between glucose production by the liver,

and glucose use by muscles, fat, brain, etc. (Knutson, 2007). Glucose tolerance is at its minimum

amount in the middle of the night, but is depended on the amount of sleep (Knutson, 2007).

During the first half of the night, glucose metabolism is slower and is opposite during the

second half (Knutson, 2007). If an individual isn’t sleeping a full night’s sleep, then they are only

completing the first half of the night and possibly part of the second half. They aren’t even

getting to the faster metabolism period of the night so they aren’t expending as much energy as

they could be.

A study on young men were subjected to six nights of four hours of sleep followed by

seven nights of 12 hours of sleep. The results were that the rate of glucose clearance was 40%

lower, glucose effectiveness was 30% lower, and insulin response to glucose was 30% lower

(Knutson, 2007). The participants had a 40% lower disposition index (DI) following the sleep

debt and three of the 11 participants had a DI value under 1,000 (Knutson, 2007). The DI value

refers to the acute insulin response to glucose multiplied by the insulin sensitivity (Knutson,

2007). DI levels in populations at high risk for type 2 diabetes are under 1000, so if the subjects

continued with the sleep debt, they could be at high risk for diabetes (Knutson, 2007).

Stress is also another aspect of life that has been increasing in people worldwide.

Approximately 50% of a United States representative sample are concerned with the amount of

stress in their lives (Adam, 2007). Excessive cortisol, commonly referred to as the stress

hormone, has been associated with disease risk as well as visceral fat accumulation (Adam,

2007). It is an inflammatory process stimulated by the growth of white adipose tissue mass in

metabolically active places, such as liver, immune system and the white adipose tissue itself

(Balistreri, 2010). Physiological cortisol concentrations stimulate body lipolysis, and in the

presence of insulin, inhibit lipid mobilization, and accumulation (Adam, 2007). This is

accomplished by the stimulation of lipoprotein lipase or by preventing the lipolytic effect of

human growth hormone (Adam, 2007).

In conclusion, it is a common phenomenon in individuals that exercise regularly to have

a higher caloric expenditure than caloric intake. By using the diet analysis and metabolic

balance calculations, I realized that I too have this imbalance. Even though it is common and

many people think that it would cause weight loss, it doesn’t always because of various other

factors. This is important information for people who do want to lose weight to focus on

everything related to their health and not just the food they put in their body. A main issue that

people all over the world are affected by is lack of sleep. Judging by the research, it has an

enormous effect on numerous other parts of the body’s health. Along with physical activity,

maintaining a healthy sleep pattern and limiting stressors in life can all come together to help

someone lose weight if that is what they desire.

References

Adam, T., & Epel, E. (2007). Stress, eating and the reward system. Physiology & Behavior, 91,

449-458. doi: 10.1016/j.physbeh.2007.04.011

Balistreri, C., Caruso, C., & Candore, G. (2010). The role of adipose tissue and adipokines in

obesity-related inflammatory diseases. Mediators of Inflammation, 1-19.

doi:10.1155/2010/802078

Benedict, C., Hallschmid, M., Lassen, A., Mahnke, C., Schultes, B., Schioth, H… Lange, T. (2011).

Acute sleep deprivation reduces energy expenditure in healthy men. American Journal of

Clinical Nutrition, 93, 1229-1236. doi: 10.3945/ajcn.110.006460

Bosy-Westphal, A., Hinrichs, S., Jauch-Chara, K., Hitze, B., Later, W., Wilms, B…Muller, M.

(2008). Influence of partial sleep deprivation on energy balance and insulin sensitivity in

healthy women. Obes Facts Obesity Facts, 1, 266-273. doi: 10.1159/000158874

Jequier, E. (2002). Leptin signaling, adiposity, and energy balance. Annals of the New York

Academy of Sciences, 967, 379-388.

Knutson, K., Spiegel, K., Penev, P., & Cauter, E. (2007). The metabolic consequences of sleep

deprivation. Sleep Medicine Reviews, 11(3), 163-178.

Laposky, A., Bass, J., Kohaka, A., & Turek, F. (2008). Sleep and circadian rhythms: Key

components in the regulation of energy metabolism. FEBS Letters, 582, 142-151. doi:

10.1016/j.febslet.2007.06.079

Markwald, R., Melanson, E., Smith, M., Higgins, J., Perreault, L., Eckel, R., & Wright, K. (2013).

Impact of insufficient sleep on total daily energy expenditure, food intake, and weight

gain. Proceedings of the National Academy of Sciences, 110(14), 5695-5700. doi:

10.1073/pnas.1216951110