An Early Dinner Can Help You Lose Weight and Improve Blood Pressure and Mood

A recent study published in JAMA Internal Medicine found that early time-restricted eating is more effective for weight loss and blood pressure improvement than the typical routine of eating for 12 hours or more. 

The findings validate recent advances in nutrition science and dietary research that call for shifting our attention from ‘what we eat’ to ‘when we eat‘  to maximize health benefits. 

What is early time-restricted eating?

Early time-restricted eating  requires you to stop eating early in the afternoon and fast for the rest of the day. This approach is based on the premise that crucial functions inside our body happen at specific time points in a day.

Hence, both early periods of feeding and longer duration of fasting are essential because secretion of digestive enzymes, gut hormones, and metabolic regulators are tightly aligned with daylight and food availability.

What did the study do?

The 14-week-long study was conducted by researchers at the Department of Nutrition Sciences at the University of Alabama at Birmingham. The study involved 90 adults with obesity who were seeking treatment. Around 80% of the study population was female.

The participants who followed early time-restricted eating ate a calorie-restricted diet within an 8-hour eating window (from 7:00 AM to 3:00 PM each day). In the comparator group, participants followed the same diet within 12 hours or more.

All the participants were advised to stay at 500 kcal below what they expend daily at rest and to exercise for 75 to 150 minutes per week.

Early time-restricted eating was more effective for losing weight than eating for 12 or more hours

The researchers found that participants who ate in an 8-hour window lost 2.3 kg more in 14 weeks than those eating over 12 or more hours. Thus, eating earlier in the day conferred approximately 50% improvement in weight loss, and was equivalent to an additional energy deficit of 214 kcal/d.

Another recent trial conducted in Guangzhou, China shows that time-restricted eating was slightly more effective for weight loss compared to calorie restriction alone, although the difference wasn’t significant. In the Guangzhou trial, participants shortened their eating window by only 2.3 hours while participants in the present study shortened their eating window by almost twice as much (4 hours and 46 minutes), which could explain why there was no significant benefit in weight loss in the Guangzhou trial.

 Eating earlier reduces blood pressure

Another significant finding of the study is that early-time restricted eating significantly reduced diastolic blood pressure compared to eating over 12 or more hours. This is aligned with another report that showed that early-time restricted eating can dramatically improve blood pressure within 5 weeks, even without a weight reduction.

The authors explain that the benefit of early-time restricted eating on blood pressure could be due to realignment of the circadian clock and enhanced excretion of salt which actually peaks during the daytime.

Diet modifications and physical activity are well known for their profound impact in controlling blood pressure. Interestingly, the blood pressure improvements due to early-time restricted eating are comparable to those achieved by the DASH diet (Dietary Approaches to Stop Hypertension), loaded with vegetables, fruits, and low-fat dairy products, and  endurance exercise.

 Early-time restricted eating improves mood 

 In the present study, people who chose to follow a calorie-restricted diet within an early eating window experienced significant improvement in mood as well as fatigue, vigor, and feelings of depression or dejection.

Most study participants wanted to continue practicing time-restricted eating after the study

In the present study, participants’ adherence to early-time restricted eating averaged six days per week.  After the study, 41% of participants in the time restriction group wanted to continue practicing time-restricted eating compared to 7% in the control group who ate restricted calories within 12 hours or more.

 Eating early in the afternoon may help you lose extra fat and conserve lean mass

A secondary analysis of findings suggested that early time-restricted eating led to an additional fat loss of 18 g/d of body and trunk fat compared to eating over 12 or more hours. This finding is consistent with another study in which people who stopped eating 4.5 hours earlier burned an extra 15 grams of fat each day. The message is straightforward. People who eat late-evening meals over a long term would progressively experience significant fat build-up compared to those who stop eating early and fast during this interval of the day.

Fasting, like any other weight loss method, may inadvertently trigger loss of soft tissue mass, muscle mass, or bone mass to a certain degree. However, this shouldn’t discourage anyone from following healthy diet regimes. With fasting, you cannot avoid muscle loss but can minimize it by increasing your intake of a protein-rich balanced diet. The present study did not observe any deleterious effects of early-time restricted eating on lean mass compared to a 12-hour eating window. This is in agreement to a previous study that found that those who lost weight with intermittent fasting lost less muscle mass compared to those who lost weight with continuous calorie restriction.

 No effect of early-time restricted eating on other parameters of heart health

The authors report no effect of early time-restricted eating on other cardiometabolic parameters such as fasting glucose levels, insulin sensitivity, fasting insulin levels, and lipid levels. The authors acknowledged the study limitation that they did not measure glucose or insulin after meals. These are the highly responsive indicators the diet is manipulated and could have added important insights to the study.

Key takeaways

1) Early time-restricted eating within an 8-hour window can help you shed extra weight and improve blood pressure.

2) It can improve your mood and vigor, and reduce feelings of exhaustion, depression and dejection.

3) Sticking with early time-restricted eating may help lose more body fat and trunk fat.

4) Study participants showed high acceptance and adherence to early time-restricted eating.

How do I get started with early time-restricted eating?

Eating dinner before 3 pm every day may not be a realistic goal for everyone. But eating within a time-restricted schedule is doable for most people and it can still be beneficial, especially if you can limit your food intake to daytime. “Eating with the sun” makes you be more in tune with your internal biological clocks, which has been shown to improve blood sugar control and reduce blood pressure. Try to have your last meal by sunset (or 6 or 7 pm) and fast until at least 7 am in the morning or later.