Counting hours rather than calories, an approach known as intermittent fasting, may help some people manage weight, according to an Arkansas Extension nutrition specialist.
Intermittent fasting focuses on when people eat rather than specific foods, said Lida Araghi, assistant professor and extension nutrition and foods specialist for the University of Arkansas System Division of Agriculture.
“Intermittent fasting is an eating pattern based on time instead of specific foods,” Araghi said. “You choose set hours to eat, and you do not eat during the fasting hours.”
Araghi said intermittent fasting can encourage the body to shift from using stored sugar, or blood glucose, to using more fat-based fuel, a process sometimes referred to as a metabolic switch.
“The method of limiting eating hours may help some people eat fewer calories without tracking calories,” she said.
Time-restricted eating using a 14- to 16-hour fasting window is being studied for potential benefits including improved insulin sensitivity and reduced inflammation. Araghi said fasting can also trigger autophagy, a process in which cells are broken down and recycled to create newer cells.
One common intermittent fasting approach is known as 16:8, which involves fasting for 16 hours and eating during an eight-hour window.
“During the fasting time, water is encouraged,” Araghi said. “Many plans also allow zero-calorie drinks like plain tea or black coffee. If a drink has sugar or calories, it breaks the fast.”
She emphasized that limiting eating hours does not mean food choices no longer matter.
“Food choices still matter because a smaller eating window does not automatically mean a healthier diet,” Araghi said.
Intermittent fasting may benefit people who prefer a simple structure with clear time rules for weight management, as well as those who want to reduce late-night snacking, she said.
However, Araghi cautioned that fasting is not appropriate for everyone. People who are pregnant or breastfeeding, under 18, at high risk of bone loss or falls, or who have a current or past eating disorder should avoid intermittent fasting. She also said people who take insulin or certain diabetes medications, including sulfonylureas, should not fast unless a clinician adjusts their treatment, due to the risk of low blood sugar.
For those interested in trying intermittent fasting, Araghi recommended starting with a 12-hour overnight fast, such as finishing dinner at 7 p.m. and eating breakfast at 7 a.m. After one to two weeks, some people may progress to a 14-hour fast with a 10-hour eating window, and eventually to 16:8 if they continue to feel well.
She advised fasters to drink water regularly and build meals around protein, fiber-rich foods such as beans, whole grains, vegetables and fruit, along with healthy fats to promote fullness.
Some people may experience side effects such as hunger, headache or irritability during the first week or two, Araghi said.
“Stop and get help if you feel faint, confused, or have signs of low blood sugar,” she said.
More information is available in the Extension fact sheet FSCS135, The Science of Intermittent Fasting.
PHOTO: Hands holding knife and fork above alarm clock on white plate on blue background. Intermittent fasting. (Adobe Stock │ #389885849 – Jo Panuwat D)
