Consistency is key to building healthy habits, and our daily meal choices may be no exception.
Researchers at Drexel University in the US have now found evidence that indulging in the same meals and snacks day after day can lead to more successful weight loss over the course of several months.
While diversity in the diet is undoubtedly important for human health, these new results suggest that eating the same meals on repeat can come with perks for those who want to lose weight.
As long as the go-to meals and snacks are well-rounded, they may help with weight loss more than a flexible, varied diet.
"Maintaining a healthy diet in today's food environment requires constant effort and self-control," says lead author and health psychologist Charlotte Hagerman from Drexel University.
"Creating routines around eating may reduce that burden and make healthy choices feel more automatic."
For the study, Hagerman and colleagues analyzed the self-reported food logs of 112 overweight or obese adults who were enrolled in a structured behavioral weight-loss program.
In the first 12 weeks of the program, participants who ate the same meals and snacks, as well as those with day-to-day calorie consistency, tended to lose more body weight than those who chose different foods, or whose calorie intake fluctuated more widely.
Specifically, those who stuck to a more routine weight-loss diet lost 5.9 percent of their body weight on average, whereas those with a more varied diet lost 4.3 percent.
That's a small overall difference, but one that could be significant, especially in the long run if this weight loss is maintained.
The study authors calculate that for every hundred-calorie difference in a participant's day-to-day diet, weight loss decreased by 0.6 percent over the study's 12-week period.
The research is small and insufficient to overturn evidence suggesting that a diverse diet holds health benefits for most people. And, of course, it's important to talk to a doctor before making any major changes to your diet.
However, it is one of the first studies to use real-time food tracking data to explore how routine eating aids weight loss across multiple months.
The findings suggest that the constant variety of food we are surrounded by, day in and day out, may be hampering some weight-loss regimens.
"If we lived in a healthier food environment, we might encourage people to have as much variety in their diet as possible," explains Hagerman.
"However, our modern food environment is too problematic. Instead, people may do best with a more repetitive diet that helps them consistently make healthier choices, even if they might sacrifice some nutritional variety."
The current study did not consider the nutritional quality of the diets participants were eating. This means that they could have been losing weight by eating an unhealthy diet.
However, participants were enrolled in a behavioral weight loss treatment program, in which they worked with coaches to determine their daily calorie intake and weekly weight-loss goals.
There were two ways participants could approach their goals: They could either keep a consistent daily calorie intake, or they could prioritize a weekly average, 'saving' some calories for special occasions.
Those who logged their food choices on the most days, which is highly predictive of weight loss, still lost more weight if they had a more routine diet.
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Researchers can't say for sure whether that weight loss is really caused by a more routine diet, but the association has them wanting to know more.
"Even a healthy diet high in variety may increase points of decision-making, making it more cumbersome to calculate calories, versus having go-to meals with pre-calculated calories," hypothesize the study authors.
Sounds like a randomized clinical trial in the making.
The study is published in Health Psychology.