It’s total calories, not when you eat
- The researchers compared weight loss diets that included either a hearty breakfast or a hearty dinner.
- Both types of diets resulted in similar weight loss and metabolic responses.
- Those who ate a larger breakfast felt fuller throughout the day, possibly making it easier to stick with the diet longer.
Should you eat your biggest meal in the morning or in the evening?
Some researchers say it doesn’t make much difference, as long as you eat the same number of calories throughout the day.
In a study published today in the journal Cell metabolismEuropean researchers tested two types of weight loss diets against each other.
Both diets included the same total number of calories each day.
But one diet caused participants to consume most of those calories in the morning, while the second had most calories in the evening.
The result? Both diets had about the same performance in terms of weight loss.
The group that ate the biggest meal in the morning, however, were significantly less hungry throughout the day.
In this study, 30 people, 16 men and 14 women, were recruited to participate, all of whom were overweight or obese but otherwise healthy.
None of the participants had diabetes, a condition that could significantly alter the results of a study of this size.
This was a real-world study, not limited to a laboratory setting, with participants under observation for four weeks.
Each individual had a fixed daily caloric intake, but some had a larger morning meal while others had a larger evening meal.
What is the size? 45% of their daily caloric intake.
Both groups’ lunches accounted for 35% of their calories while their small meal accounted for 20%.
All participants got about 30% of their calories from protein and 35% each from carbs and fat.
At the end of the study, the weight loss results for each group were comparable.
However, the group that had larger meals in the morning showed a decrease in ghrelin – a hormone that makes you feel hungry – during the day, while they also had an increase in hormones that make you feel full.
These participants also had slower gastric emptying, meaning their food spent more time in their stomach before entering the rest of the digestive tract.
The researchers said this was an important finding, as previous studies have suggested that loading up your calories in the morning leads to increased weight loss.
Emily Feivor, RD, a registered dietitian at Long Island Jewish Forest Hills in Queens, which is part of Northwell Health in New York, told Healthline she was not surprised by the results.
“The idea of controlling hunger with balanced meals at structured meal times can be a significant aid in achieving proper portion sizes and intakes throughout the day, which is the ‘secret’ of dieting the most. most efficient and easiest,” Feivor said.
Lori Welstead, MS, RD, LDN, registered dietitian and nutritionist in the Section of Gastroenterology, Hepatology and Nutrition at UChicago Medicine, told Healthline, “It’s a challenge to study nutrition and metabolism in human subjects. We are not as simple as mouse models or as it may seem in the laboratory.
“This was the first study of its kind and helps build knowledge to provide the foundation for further studies,” Welstead added.
She noted that the researchers admittedly couldn’t measure things like glucose in the group that ate larger evening meals because the participants had to fall asleep.
Megan Wroe, MS, RD, CNE, CLEC, wellness manager and dietician at the Wellness Center at Providence St. Jude Medical Center in Fullerton, Calif., told Healthline she agrees that this study raised interesting questions for future research.
“I would like to see the authors take this study further now and evaluate the results of breakfast meals with various macronutrient compositions. A high-fat, high-protein, and high-carb breakfast can lead to very different results” , Wroe said.
It’s one thing to study weight loss diets. It’s another to be on one.
Although a larger breakfast may make it easier to maintain a specific diet, it is important to remember that in this study, total daily calories were strictly controlled.
Experts say eating a hearty breakfast without making other lifestyle changes is unlikely to have a significant positive effect on your health.
“Breakfast should include the basics: a high fiber content of fruits/vegetables or whole grains, along with a good amount of protein and heart-healthy fats,” Feivor says.
“Beware of the breakfast pitfalls of high-sugar/low-fiber cereals, fruit juices (even 100%), pastries and highly processed meats,” she warned.
“Listen to your body. If you are hungry, eat. If you are full, stop. It takes about 20 minutes to really notice that signal,” Welstead said.
“Many weight loss diets aren’t geared towards long-lasting lifestyle changes and are quick fixes. If it sounds too good to be true, it probably is,” Welstead added.
The importance of physical activity cannot be ignored either.
“Improved heart rate, increased energy and mood, reduced stress levels, increased muscle tone, reduced visceral fat and improved metabolic markers such that blood sugar and blood pressure are all common potential benefits of increased physical activity even if there is no weight loss associated with it,” Wroe said.
“Weight loss diets almost never create weight loss if there is no change in the way the person eats. There is only how far caloric restriction can go, regardless of when those calories are spread throughout the day,” she added.