Does Eating the Same Foods Work Best for Weight Loss?

 Repeating the same meals and keeping calorie intake steady produced more weight loss than eating a more varied diet among individuals living with overweight or obesity, a short-term trial showed.

“Conventional wisdom around dieting says you should incorporate a lot of different foods to avoid getting bored and that you should splurge on the weekends or special occasions so you don’t feel as deprived,” lead author Charlotte Hagerman, PhD, of the Oregon Research Institute, Springfield, Oregon, told Medscape Medical News. “This contradicts research showing that consistency makes your behavior more habitual, that is, more automatic or effortless.

“We wanted to formally test these competing ideas in a group of people trying to lose weight,” she explained. “Maintaining a healthy diet in today’s food environment requires constant effort and self-control. Creating routines around eating may reduce that burden and make healthy choices feel more automatic.”

Study participants who repeated many of the same foods and kept calories consistent lost more weight over 12 weeks (5.9% vs 4.3% of their body weight) than those with more varied meals.

“When it comes to weight loss, consistency may matter more than variety,” Hagerman said.The study was published online in Health Psychology.

‘Routinized Eating May Facilitate Success’

Researchers analyzed real-time food logs from 112 adults with overweight or obesity who were enrolled in a long-term, structured behavioral weight-loss program. Participants’ mean age was 53 years, the mean BMI was 34.5, and most (85%) were female.

The investigators focused on the first 12 weeks of the program because previous studies showed that this period is long enough to achieve meaningful weight loss and because food tracking adherence tends to decline and become unreliable after the initial period of motivation.

Participants were asked to track everything they ate each day using a mobile app and to do daily weigh-ins using a wireless scale. A full day of tracking was defined as at least 800 calories per day for at least 75% of the study days.

The researchers then measured how “routinized” each person’s diet was in two ways. First, they looked at caloric stability, or how much a person’s daily calorie intake fluctuated from day to day and between weekdays and weekends.

Next, they examined dietary repetition — the percentage of unique foods tracked and percentage of foods logged 10+ times.

Greater dietary repetition and more daily calorie stability were associated with higher weight loss. Those who repeated many of the same foods rather than eating a wide variety lost more weight (5.9% vs 4.3% of their body weight) than those whose diets were more varied.

Specifically, for every 10% decrease in the proportion of foods that were unique (eg, from 15% to 5%), the total weight loss percentage was expected to increase by 0.5%.

However, contrary to expectations, participants with higher weekend-to-weekday deviations also had greater weight loss — a finding that could be “misleading,” according to the authors.

“Previous studies show that people who track their food more carefully tend to lose more weight,” said Hagerman. “Food tracking tends to decline on the weekends, when people are more likely to be eating at restaurants, at friends’ houses, etc. Therefore, higher calories tracked on the weekends may not actually be evidence that the person ate more; rather, that they were just more diligent about tracking their calories.”

The study had several limitations. The selection process, which excluded participants who tracked for fewer than 75% of days, may have created a biased sample of highly motivated participants. All measures involving calorie intake were also expected to be biased, the authors wrote, because people typically underestimate the number of calories they consumed.

Measures of dietary repetition may also have been biased if or when participants failed to track entire meals and snacks. And because the study was correlational, causality cannot be assumed.

Despite the limitations, the authors wrote, “Overall, findings suggest that more routinized eating patterns during a weight-loss attempt may facilitate success.”

‘Dietary Variety Still Important’

Commenting on the study for Medscape Medical News, Amanda Velazquez, MD, director of obesity medicine at the Center for Weight Management and Metabolic Health at Cedars-Sinai, Los Angeles, said, “Consistency in approximate calorie intake matters, in part because it may affect the physiology of the body’s anticipation of the quantity of nutrition it will receive. Also, regularity in meal timing may be helpful (timing was not assessed in this study), as the body can better anticipate nourishment when intake is more predictable.”

“In clinical practice, this kind of consistency appears to be important not only for weight loss but also for long-term weight-loss maintenance,” she added.

That said, Velazquez, who was not involved in the study, noted that the message “consistency may matter more than variety” could be misinterpreted. “Dietary variety still has important benefits, including supporting overall diet quality and likely promoting a healthier microbiome.”

“Ideally,” she said, “the goal would be a dietary pattern that includes variety in foods and colors, while also maintaining relatively consistent calorie intake and meal timing.”

The study’s short duration meant it was difficult to know whether the findings would persist over the long term, especially for weight maintenance, she noted. Furthermore, the study did not account for the healthfulness of the repeated foods, which could influence cardiometabolic health, and the weight-loss findings might differ depending on the types of food that are repeated.

“In this study, daily calorie stability and dietary repetition were associated with greater weight loss,” Velazquez said. “This may represent one useful behavioral strategy to discuss with select patients, particularly those who prefer routine and do well with repetitive eating patterns. Ultimately, individualized, precision nutrition care is indicated.”

This research is a secondary analysis of data originally collected under a clinical trial funded by the National Institute of Diabetes and Digestive and Kidney Diseases. The secondary analysis received additional funding. Hagerman declared having no conflicts of interest. Velazquez reported being an advisory board member of Intellihealth.

https://www.medscape.com/viewarticle/does-eating-same-foods-work-best-weight-loss-2026a10009f4