Study suggests that time-restricted eating produces more weight loss than calorie counting.
Losing weight is a common goal among individuals with type 2 diabetes, given the condition’s strong correlation with overweight and obesity. However, it hasn’t been clear what dieting strategy works best for people with this metabolic disorder.
A recent randomized controlled study of type 2 diabetes patients showed that study participants who restricted eating to between noon and 8 p.m. daily lost more weight than those who reduced their overall calorie intake by counting calories. Interestingly, both methods displayed similar improvements in blood sugar levels.
“Many people find counting calories very hard to stick to in the long term, but our study shows that watching the clock may offer a simple way to decrease calories and lose weight,” said Vicky Pavlou, RDN, a doctoral student at the University of Illinois at Chicago who performed the new research. “Although time-restricted eating is becoming increasingly popular, no other studies have looked at an eight-hour eating window in people with type 2 diabetes.”
Pavlou presented the findings at NUTRITION 2023, the annual flagship meeting of the American Society for Nutrition.
Previous Studies and New Discoveries
Time-restricted eating within an eight-hour window has previously been studied in individuals battling obesity. Nonetheless, this new research initiative, led by Krista Varady, a nutrition professor at the University of Illinois at Chicago, aimed to discern the potential benefits of this strategy for those with type 2 diabetes.
The study included a group of 75 people, ranging from 18 to 80 years old, representing diverse racial and ethnic backgrounds, all of whom were diagnosed with obesity and type 2 diabetes. Participants were placed into one of three groups: time-restricted eating, calorie restriction, or control. The people in the time-restricted eating group ate only between noon and 8 p.m. while the calorie restriction group could eat at any time of the day but counted their calories on the MyFitnessPal mobile app with a goal of reducing their caloric intake by 25% of their maintenance calories — the calories needed to maintain their current weight. The control group continued eating their normal diet.
Following the six-month investigation, the team discovered that participants observing the time-restricted eating diet lost 3.55% of their body weight relative to the control group. This would be the equivalent of a person weighing 275 pounds losing just under 10 pounds. The calorie restriction group did not lose any weight relative to the control group. Compared to the control group, blood sugar (HbA1C) levels decreased in both the time-restricted group (-.91%) and the calorie restriction group (-.95%).
Cardiometabolic Risk Factors and Precautions
The researchers also assessed whether these diet strategies improved cardiometabolic risk factors, but the weight loss achieved with the time-restricted eating did not reach the 5% mark typically necessary for improvement in these factors. Also, the study participants were taking cholesterol and blood pressure medications, which makes it difficult to observe improvements in cardiometabolic risk factors.
“Our study shows that time-restricted eating can be a good alternative for those with type 2 diabetes who want to lose weight and improve their blood sugar,” said Pavlou. “However, there are multiple types of medications for those with type 2 diabetes, some of which can cause low blood sugar and some that need to be taken with food. Therefore, it is important to work closely with a dietitian or doctor when implementing this dieting approach.”