Another great option for losing weight and better health may be to only eat within a 10 hour window, and then not eat for 14 hours (thus a nightly 14 hour fast). Many may find this easier than traditional dieting (counting calories and restricting eating). Just eat breakfast later, supper earlier, and no snacks in the evening. (But water is OK.)
Researchers from the Univ. Of California and Salk Institute conducted the 10-hour restricted eating study on persons with metabolic syndrome, most of whom were also on high blood pressure (anti-hypertensive) medicine and statins. After 12 weeks the people had lost weight, lost body fat, lowered blood pressure, reduced cholesterol, and decreased the size of their waist.
Since metabolic syndrome raises the risk for diabetes and heart (cardiovascular) disease, then 10-hour restricted eating can be an important tool to improve health. The researchers point out that in animal studies, time-restricted feeding can prevent and reverse aspects of metabolic diseases, and in healthy humans, it reduces the risks of metabolic diseases. Studies also found benefits with 9-hour restricted eating and 12 hour fasts.
Metabolic syndrome affects nearly 30 percent of the U.S. population, and increases the risk for type 2 diabetes, heart disease and stroke. But lifestyle interventions such as adopting a healthy diet and increasing physical exercise are difficult to maintain and, even when combined with medication, are often insufficient to fully manage the disease.
Now, in a collaborative effort, researchers from the Salk Institute and the UC San Diego School of Medicine found that a 10-hour time-restricted eating intervention, when combined with traditional medications, resulted in weight loss, reduced abdominal fat, lower blood pressure and cholesterol, and more stable blood sugar and insulin levels for participants. The pilot study, published in Cell Metabolism on December 5, 2019, could lead to a new treatment option for metabolic syndrome patients who are at risk for developing life-altering and costly medical conditions such as diabetes.
Time-restricted eating (eating all calories within a consistent 10-hour window) supports an individual's circadian rhythms and can maximize health benefits, as evidenced by previous research published by the Salk team. Circadian rhythms are the 24-hour cycles of biological processes that affect nearly every cell in the body. Increasingly, scientists are finding that erratic eating patterns can disrupt this system and increase the risk for metabolic syndrome and other metabolic disorders with such symptoms as increased abdominal fat, abnormal cholesterol or triglycerides, and high blood pressure and blood sugar levels.
"Eating and drinking everything (except water) within a consistent 10-hour window allows your body to rest and restore for 14 hours at night. Your body can also anticipate when you will eat so it can prepare to optimize metabolism," says Emily Manoogian, the paper's co-first author and a postdoctoral fellow in the Panda lab. "We wanted to know if controlling the timing of food intake to support circadian rhythms would improve the health of individuals that were already being treated for cardiometabolic diseases."
"We suspected a 10-hour eating intervention might be beneficial because of Satchidananda Panda's pioneering work in animals, which showed that time-restricted eating led to dramatic health benefits, including a healthier metabolism," adds Michael Wilkinson, co-first author, assistant clinical professor of medicine at UC San Diego School of Medicine and a cardiologist at UC San Diego Health.
The pilot study included 19 participants (13 men and 6 women) diagnosed with metabolic syndrome who self-reported eating during a time window of more than 14 hours per day. Additionally, 84 percent of participants were taking at least one medication such as a statin or an antihypertensive therapy. Study participants used the Panda lab's myCircadianClock app to log when and what they ate during an initial 2-week baseline period followed by the three-month, 10-hour time-restricted eating intervention. Nearly 86 percent of participants correctly logged their food using the app, indicating high compliance throughout the study.
Participants did not report any adverse effects during the intervention. To reduce food intake to the 10-hour window, most participants delayed their first meal and advanced their last meal each day, so meals were not skipped. Although calories were not recommended to be reduced for the intervention, some participants did report eating less, likely due to the shorter eating window.
Overall, participants experienced improved sleep as well as a 3-4 percent reduction in body weight, body mass index, abdominal fat and waist circumference. Major risk factors for heart disease were diminished as participants showed reduced blood pressure and total cholesterol. Blood sugar levels and insulin levels also showed a trend toward improvement.