It’s not just how often you work out or how hard that affects how much belly fat you have on your waist and tummy – your sleep habits are a factor too. Even if you’re eating cleanly and exercising regularly, you may still have problems shedding stubborn belly fat if you’re not getting enough sleep.
Need convincing? A study published in the journal Sleep showed that young Hispanic and black adults who slept for five hours or less gained more belly fat over a five-year period than those who slept six hours or more each night. The participants gained both superficial belly fat, the kind that jiggles, and deeper abdominal fat called visceral fat that increases the risk for health problems like heart disease and type 2-diabetes.
Visceral fat is a “marker” for future health problems and a sign that you may have some degree of insulin resistance. If you’re seeing a “muffin top” where there was none before or watching your waist size grow, use it as a wake-up call re-evaluate your diet, exercise plan, stress level, AND your sleep habits.
How does lack of sleep contribute to belly fat accumulation? As it turns out, there are four main ways inadequate sleep makes it harder to trim your belly.
Ways Lack of Sleep Makes It Harder to Lose Belly Fat
When you don’t sleep enough or have chronically poor sleep quality, it boosts levels of cortisol, a hormone released in response to stress. Cortisol does the dirty job of increasing the amount of visceral abdominal fat you carry deep in your belly. That’s not only bad for your waistline, but damaging to your health as well. Elevated cortisol levels increase insulin resistance and the risk of metabolic syndrome, a condition that’s a precursor to heart disease and type 2 diabetes. Cortisol also suppresses immunity and predisposes you to catching every cold and flu virus that passes around.
Another way sleeping too little increases belly fat is by suppressing the release of growth hormone. Growth hormone is an anabolic hormone that boosts muscle growth, but it’s also a fat-burning hormone that helps keep your tummy and waistline trim. Growth hormone levels rise during deep sleep, so if you’re not getting enough sleep, growth hormone levels can be affected. This makes it harder to build muscle and lose body fat even if you lift heavy weights.
Research also ties falling growth hormone levels to many of the effects we associate with aging – increase in body fat, loss of muscle tissue and skin sagging due to a reduction in collagen production. Best to get your beauty sleep! To maximize growth hormone production, it’s important to not only sleep enough but get enough DEEP sleep. Sleep quality counts.
Skimping on sleep also alters levels of appetite hormones like leptin and ghrelin that control your appetite. Sleeping too little increases cravings for carby foods and the desire to consume empty calories. If you’re sleep deprived and hunger strikes, you’re more likely to make food choices that are less waistline-friendly and do more mindless nibbling. One study found women who got only 4 hours of sleep ate an additional 329 calories the next day. Think about how that could add up over time!
You’re also less likely to put forth maximal effort when you work out if you’re sleep deprived. It’s not easy to push yourself when what you could really use is a good night’s sleep. You may find yourself going through the motions of working out instead of giving it your best effort. High-intensity sweat sessions combined with heavy resistance training can help you lose belly fat, but only if you’re energetic enough to do them. Plus, your muscles need downtime to recover – that’s where sleep comes in.
How Much Sleep Do You Need?
Most people need between 7 and 8 hours of sleep a night. Research shows people who get this amount of sleep have a lower risk of health problems compared to people who sleep more or less. If you’re sleeping less than 6 hours a night, it may be harder to lose belly fat and control your weight in general. Plus, you may be putting yourself at risk for health problems like type 2 diabetes and heart disease.
Tips for Improving Your Sleep Quality
Go to bed at roughly the same time each night, even on weekends. Get up at the same time too. You’ll enjoy better quality sleep if you have a consistent sleep schedule.
Reinforce your body’s natural circadian rhythms by exposing your eyes to light as much as possible during the day. Throw the blinds open and let natural light in. Take an outdoor walk during the day. At night, reduce light exposure after 10:00 P.M. Shut down the computer and turn in. Sleep in a completely dark room.
Keep the temperature in your bedroom around 65 degrees F. Research shows this temperature is optimal for sleep.
Avoid drinking liquids two hours before bedtime. Otherwise, your sleep may be interrupted by trips to the bathroom. Don’t drink caffeinated beverages after lunch.
Avoid eating after dinner, especially if you’re prone towards heartburn.
Make sure your bedroom is comfy. Invest in silky sheets and pillowcases that feel good against your skin.
The Bottom Line?
Work hard at the gym, but don’t overlook the importance of getting enough sleep and giving your body adequate rest time. Getting flat abs and a more defined waistline takes a clean diet and focused exercise plan – but you need time to recover too. Don’t skimp on sleep, and make sure the sleep you do get is high quality.
AJP – Endo August 2008 vol. 295 no. 2 E385-E392.
J Clin Endocrinol Metab. 1996 Sep;81(9):3239-43.
J Clin Endocrinol Metab. 2004;89:5762-5771.
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