Sweet Dreams: The Relationship between Sleep Health and Your Weight Jason C. Ong, PhD Associate Professor Department of Neurology Center for Circadian and Sleep Medicine Northwestern University Feinberg School of Medicine What happens in the body when we sleep? 1
Circadian Rhythms: Body Clocks 2011 by American Physiological Society 2
What happens in the body when we sleep? Active regulation of hormones and metabolism during sleep Growth hormone is released shortly after sleep onset Cortisol is generally low in the evening and peaks in the morning Sleep is an ACTIVE process Balance Regulation 3
ENERGY BALANCE is important to weight management Energy Intake = Energy Expenditure appetite regulation Courtesy of Kristen Knutson, PhD Energy Intake ENERGY IMBALANCE Weight Gain > Energy Expenditure appetite regulation Courtesy of Kristen Knutson, PhD 4
Sleep Energy Intake Energy Expenditure appetite regulation Courtesy of Kristen Knutson, PhD How is sleep related to weight management? Is it the amount of sleep? Does the quality of sleep matter? What are the biological mechanisms? 5
Is there a relationship between the amount of sleep and risk of obesity? 6
Sleep Duration & Obesity in the U.S. Sleep (hours) 9 8 7 6 Sleep Obesity 35% 30% 25% 20% 15% 10% 5 0% 1950 1960 1970 1980 1990 2000 2010 5% Obesity Prevalence 7
Luyster et al., 2012 How is short sleep related to the risk of obesity? 8
Does short sleep dysregulate hormones? Hypothesis: Short sleep duration causes dysregulation of important hormones related to appetite and metabolism. Evidence: Strong Glucose Metabolism Reducing sleep to < 6 hours can impair glucose tolerance Individuals with family history of diabetes and < 6 hours of habitual sleep are more susceptible to developing diabetes Short sleep (< 6 hours) increases the risk for Type 2 diabetes by 28% Hormones involved in appetite regulation Ghrelin: promotes appetite (hunger) Leptin: regulates satiety (fullness) Does short sleep increase energy intake? Hypothesis 1: Short sleep increases appetite which leads to more food intake. Evidence: Strong Greater food intake with sleep < 6 hours per day Associated with ghrelin and leptin Hypothesis 2: Less sleep means more time awake to eat. Evidence: Weak Increase food intake does not seem to be just due to more time awake Appetite for high-calorie, carbohydrate-rich foods increased more than other types of food 9
Does short sleep decrease energy expenditure? Hypothesis: Lack of sleep reduces the energy to engage in physical activity, leading to less physical activity. Evidence: Inconclusive One study found that reducing sleep to < 5 hours in bed for two nights resulted in less physical activity (intensity, amount) Other studies have not found differences in energy expenditure Is there a relationship between the quality of sleep and risk of obesity? 10
Sleep Quality and Metabolic Factors Hypothesis: Poor sleep quality causes dysregulation of important hormones related to appetite and metabolism. Evidence: Moderate (only a few studies available) Reduction in slow-wave sleep (deep sleep) without changes in the amount of sleep can impair glucose tolerance Self-reported difficulty falling or staying asleep is associated with 57% to 84% increased risk for diabetes 11
Can insufficient sleep impact weight management interventions? 12
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Disturbed or Insufficient Sleep Food Intake Hormonal Dysregulation Brain glucose utilization Nocturnal GH Nocturnal Cortisol Sympathetic nervous activity Appetite Altered Glucose Metabolism Insulin Secretion Weight gain Insulin Resistance Obesity Type 2 Diabetes Adapted from Knutson (2010) 14
Clinical Aspects of Sleep and Weight Management What can disturb sleep? Medical conditions Chronic pain, pulmonary diseases, cancer Psychiatric conditions Mood disorders, anxiety disorders Medication/substances Stimulants, caffeine, corticosteroids Lifestyle Factors Stress Behavioral choices Technology 15
Sleep Disorders Primary Symptoms Disorders Class Loud snoring, waking with choking sensation, daytime sleepiness Strange sensations in legs, kicking feet and legs during sleep Sleep Apnea Restless Legs Syndrome Periodic Limb Movement Disorder Sleep-related breathing disorder Sleep-related movement disorder Too sleepy during the day Narcolepsy Hypersomnia Unusual events that occur in the night Can t fall asleep or stay asleep Sleepwalking Primary Insomnia Parasomnias Insomnias Obstructive Sleep Apnea (OSA) Sleep disruption due to repetitive respiratory events Common Symptoms Loud snoring Partner may notice pauses in breathing (witnessed apneas) Waking with a choking or gasping feeling Difficulty staying asleep Excessive daytime sleepiness Risk Factors BMI > 30 Male Age > 40 Crowded oropharynx 16
Continuous Positive Airway Pressure (CPAP) OSA and Obesity OSA causes poor sleep quality, which is associated with disturbances in appetite regulation (ghrelin, leptin) Treatment using CPAP may improve regulation of ghrelin and leptin Not consistent across studies Is weight loss an effective treatment for OSA? 17
How can you improve your sleep health? Make sure that you are SATED Satisfied Alert Timing Efficiency Duration 18
Is your sleep Satisfactory? Do you feel refreshed? Are you allocating enough time for sleep? Tips: Make sleep health a priority! Set aside a regular time for sleep Are you Alert during waking hours? Does it take effort to stay awake? Are you falling asleep unintentionally? Do you need to consume caffeine to stay alert? Tips: Avoid excessive use of stimulants Avoid excessive napping > 30 minutes Be aware of sleepiness when operating a motor vehicle 19
Is the Timing of sleep right for you? Does your biological clock line up with your current time zone? Tips: Pay attention to light exposure at night Know your own feel-good rhythm (owls and larks) Are you Efficient at sleeping? Do you spend more than 30 minutes awake while trying to sleep? Tips: Try going to bed only when you are sleepy. Avoid lingering in bed if you are not sleepy. 20
Are you getting adequate sleep Duration? Are you getting enough sleep for your age? Most adults need about 7 to 9 hours of sleep per day. Tips: Set aside enough time for sleep Work on time management and stress management during the daytime If you are not regularly SATED and these tips do not help, consider seeking professional help. Take Home Points Sleep is an active process of balance and regulation Insufficient sleep (quantity and quality) can impact weight management in several ways Appetite dysregulation can lead to weight gain Reduce effectiveness of weight loss interventions Are you SATED? 21
Thank you! 22