Until today in this blog and in many media outlets you have read or heard ‘exercise with diet’ is the only way to lose weight. Well, I’ve got news from a group of researchers who state that eating within a specific eight-hour window can cause weight loss.
In a recently published JAMA Internal Medicine article, eating within a 12-hour time frame was compared to limiting caloric intake to an eight-hour time frame (7 AM to 3 PM in this study). Using the eight-hour window, individuals lost an additional 5 pounds over 14 weeks. The eight-hour window, however, wasn’t much help for shedding body fat specifically but a bonus was the lowering of the diastolic blood pressure (the second number in BP reading – the minimum pressure during relaxation and dilatation of the heart when the ventricles fill with blood). No other cardiovascular benefits were noted in the study details. The study include 59 participants, and as I stated above, ran for a 14-week period. I think it is especially noteworthy that an improved mood and sleep pattern were also seen. The detailed evaluation noted improved sub-scores for mood, vigor vs. activity, and fatigue vs. inertia. But this can have a subjective component, I feel. Important to note that within the study not everyone complied for seven days per week, the average was six days per week eating during the eight-hour period.
An earlier study this year (published New England Journal of Medicine), used the same concept – a time-restricted diet but adding a caloric restriction based on individuals’ activity level. In this study there were 90 participants, mean age of 43 – and 80% were women, all with BMIs from 30 to 60. All participants received weight loss counseling and energy restrictions followed by a caloric restricted diet of 500 cal per day below their energy expenditure. They were exercising 75 to 150 minutes per week depending on their baseline physical activity. They were analyzed for how much they exercised and they were restricted to eating from 8 AM to 4 PM.
However, these researchers found it didn’t result in a significantly greater amount of weight loss compared to just limiting your total caloric intake. Differing outcomes from similar studies are frequent in the medical literature. A careful review of specifics and outcomes is quite important for readers.
One difference between the two trials was the eight-hour time frame, the trial published in the New England Journal of Medicine studied it from 8 AM to 4 PM versus the 7 AM to 3 PM trial in JAMA Internal Medicine. So the question becomes does timing matter when it comes to eating? It matters. Regardless of the study differences, I believe the existence of benefits from adherence to a consistently limited eating time is best for our bodies.
Having your caloric intake limited according to energy expenditure appears to be relevant for weight loss. Hope this blog arms you with insights to help in your diet.
I always like hearing your comments!