Many of us look at our eating habits because we want to lose weight or “have more energy,” which are totally valid reasons for making changes. Food impacts so many health conditions from arthritis to obesity and without adequate or balanced nutrition, weight and energy levels are certainly affected. But what we may not realize is that diet and exercise are only part of the solution. Hitting the sack at a normal hour is equally important to whittling our waistlines and raising our energy levels as hitting the gym. Without adequate sleep, we may not have the energy to exercise, right?
Recent research published in the International Journal of Obesity, finds a link between poor or interrupted sleep and reduced ability to lose weight. In the PREDIMED study of nearly 2,000 overweight or obese subjects with average age of 65 years that also had metabolic issues including high blood pressure, elevated insulin levels, poor glucose levels, and dyslipidemia. The subjects participated in a weight loss program for 12 months and were advised to follow a low-calorie Mediterranean diet in addition to an exercise and behavioral modification program.
In addition to monitoring weight loss, the subjects’ sleep habits were also investigated. Researchers found that subjects with interrupted or poor sleep, lost less weight than those with adequate sleep. Subjects with inconsistent sleep habits (known as “sleep variability”) lost less weight than those with regular sleeping habits. Subjects that slept less than 6 hours had higher waist circumference than those with 7 to 8 hours of sleep per night.
Inadequate sleep is also associated with elevations in blood sugar in both adults and adolescents. A review of 23 studies on sleep architecture (defined as the structured organization of normal sleep including rapid eye movement [REM sleep] and non-rapid eye movement sleep), found that inadequate REM sleep is associated with insulin resistance in teens.
Sleep architecture changes with age as does sleep efficiency. Older people tend to go to bed earlier and wake earlier. A systematic review and meta-analysis found that sleep disturbances were a significant risk factor for elevations in blood sugar. Those with trouble falling asleep had a 55% increase in type 2 diabetes while difficulty staying asleep resulted in a 74% increased risk. Individuals with diabetes also tend to have more sleep disturbances. Factors that contribute to poor sleep in diabetics include restless leg syndrome, nocturia, peripheral neuropathy, and changes in blood sugar.
In addition to weight gain and poor blood sugar management, lack of ZZZs has also been implicated in risk for heart disease.
A 2019 study on mice published in Nature, found that interrupted sleep alters levels of orexin, also known as hypocretin, a hormone associated with wakefulness. A decline in hypocretin is linked to an increase in a signaling protein, which impacts white blood cells and inflammation. Inflammation was associated with atherosclerosis in sleep-deprived mice, despite no changes in cholesterol, blood glucose and blood pressure.
Some research supports certain dietary patterns may impact sleep. A 2016 study published in Advanced Nutrition suggests that a Mediterranean diet including fruits and vegetables high in vitamin C, whole grains and fatty fish, may improve sleep. Carbohydrate manipulation (low and high carbohydrate diets) has been shown to affect REM sleep and slow-wave sleep. Slow-wave sleep is deep sleep that is restorative, while REM sleep impacts memory. However, the type of carbohydrate makes a difference. Highly processed carbohydrates and higher fat foods (such as French fries or high fat desserts) have been linked with poor sleep, while fruit and whole grains tend to improve sleep patterns (5). Reducing caffeine intake (especially after 2 PM) may also aid in improving sleep habits. Scientists believe more research is needed in this area as data for this type of research often relies on self-reports.
So, what can we do to improve sleep hygiene?
- Make sleep a priority! Experts suggest 7-8 hours per night.
- Avoid caffeine after 2 PM to prevent insomnia
- Limit intake of highly-processed carbs and high-fat foods, especially at night
- Turn off cell phones, TVs, and other screens a few hours before bed. Blue light stimulates the brain and may keep people awake.
- Get regular exercise. This aids with stress management and improves sleep quality and duration according to several studies.
By Lisa Andrews, MEd, RD, LD
Copyright foodandhealth.com, reprinted with permission.