New research shows that the time of day food is eaten is more critical to weight loss than the number of calories consumed.
In a recent study from the University of Texas Southwestern Medical Center in Dallas, researchers have found evidence that connects meal times with the ability to lose weight.
Findings also support the idea that the body’s natural sleep cycles are disrupted when food is consumed at irregular times.
Weight Loss Variables
Previous research has confirmed that eating a calorie-restricted diet can increase longevity. The researchers at UT Southwestern Medical Center wanted to further explore the relationship between body rhythms, like the circadian cycle, and the time of day calories are consumed.
These types of studies can be difficult to structure. To get the most accurate results from a feeding study, animal subjects would be used and have to be hand-fed and observed constantly.
Researchers from the study wanted to simulate long-term results in a way that could be measured during normal working hours for a person. An automated feeding system was developed that allowed researchers to control the food intake of the different test groups. There were also sensors that helped track the movements, reactions, and record food consumption time of the lab animals.
Animal Observation Study
The study consisted of five groups of lab animals. Each group was assigned a unique eating regime that varied by calorie content and feeding time. Data analysis showed the group of mice that received reduced-calorie nighttime feedings was the only group to display weight loss.
Two other groups of animals received feedings during daylight hours. Weight loss did not occur in these groups because rats are nocturnal, therefore eating during the day is a disruption of their natural cycle. These groups were observed to remain as active at night as they were during the day, which led to sleep deprivation. Researchers believe the lack of sleep is a symptom of disrupted circadian rhythms and metabolism.
Circadian rhythms, otherwise known as our “internal clock,” is a set of biological activities that regulate cycles of sleep and waking. Previous studies suggest that this internal sense of time also influences other body processes, like digestion and metabolism. The current study adds weight to those theories.
According to Dr. Joseph S. Takahashi, Chairman of Neuroscience at UT Southwestern, these studies suggest that dieting will only be effective if calories are consumed during the daytime when we are awake and active. They further suggest that eating at the wrong time at night will not lead to weight loss even when we are dieting.
Further Research
The study shows a link between weight loss and when we eat. The researchers believe the study’s greatest contribution may be the automated feeding system. The automated feeding system allows future researchers to conduct longer and more biologically accurate experiments that can be scaled up for large and very long longevity studies. This provides the means to ask questions about what mechanisms extend lifespan in mammals, and whether it is actually the calorie reduction or the time at which food is consumed that extends lifespan. We look forward to seeing more of this research.
