Routine Diet May Support Weight Loss, Drexel University Study Finds

Consistency plays an important part in forming healthy habits, and everyday food choices may follow the same pattern.

Researchers at Drexel University in the US have found evidence that eating identical meals and snacks repeatedly could result in more successful weight loss over several months.

Although dietary variety is unquestionably valuable for human health, the new findings indicate that repeating the same meals may offer benefits to people aiming to lose weight. Provided that regular meals and snacks are nutritionally balanced, they could support weight loss more effectively than a flexible, varied diet.

Routine diets and weight loss

"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 research, Hagerman and her colleagues examined self-reported food diaries from 112 adults with overweight or obesity who were taking part in a structured behavioural weight-loss programme.

During the programme's first 12 weeks, participants who repeatedly ate the same meals and snacks generally lost more weight than those selecting different foods. The same applied to people whose calorie intake remained stable from one day to the next, compared with those whose intake varied more substantially.

More precisely, participants following a more routine weight-loss diet lost an average of 5.9 percent of their body weight, while those eating a more varied diet lost 4.3 percent.

This is a modest difference overall, yet it could matter considerably over the longer term, particularly if the lost weight is kept off.

The authors calculated that each hundred-calorie variation in a participant's daily diet was associated with a 0.6 percent reduction in weight loss during the study's 12-week period.

Food variety in the modern food environment

The study was small and does not provide enough evidence to challenge research indicating that dietary diversity benefits most people’s health. Naturally, anyone considering substantial dietary changes should first consult a doctor.

Nevertheless, it is among the first studies to use real-time food-tracking information to investigate how habitual eating supports weight loss over a period of several months.

Its results suggest that the unrelenting food variety surrounding us every day could be undermining some weight-loss plans.

"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."

Limits of the Drexel University study

The researchers did not assess the nutritional quality of participants’ diets. Consequently, it is possible that some participants lost weight while following an unhealthy diet.

However, all participants were enrolled in a behavioural weight-loss treatment programme, where coaches helped them establish daily calorie targets and weekly weight-loss goals.

Participants had two options for meeting these goals. They could maintain a consistent calorie intake each day, or focus on a weekly average by ‘saving’ calories for special occasions.

Even among those who recorded their food choices on the greatest number of days-a behaviour strongly predictive of weight loss-participants with more routine diets still lost more weight.

Researchers cannot confirm that the additional weight loss was directly caused by following a more routine diet, but the association has prompted further questions.

"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.

It sounds like the basis for a randomised clinical trial.

The study is published in Health Psychology.