- Despite the growing popularity of GLP-1 medications for weight loss, many people prefer to stick to a Healthy diet instead.
- A new study found that eating many of the same meals and a consistent number of calories every day may help in losing weight more than consuming a more varied diet.
- Researchers also discovered that participants who logged higher calorie totals on the weekends than during the week also lost more weight.
Despite the growing popularity of glucagon-like peptide-1 (GLP-1) receptor agonist medications like Zepbound and Wegovy for helping to lose weight, many people prefer instead to stick to following a Healthy food pattern, like the Mediterranean diet or intermittent fasting, to assist them with weight loss.
“GLP-1 medications are an amazing tool for weight loss, but not everyone is interested in using medication, and there are concerns about cost and side effects to consider,” Charlotte Hagerman, PhD, research scientist at the Oregon Research Institute, told Medical News Today. Using behavioral strategies to change your diet is often still the preferred first strategy for weight loss.”
Hagerman is the lead author of a new study published in the journal Health Psychology that found that eating many of the same meals and a consistent number of calories every day may help with weight loss more than consuming a more varied diet.
For this study, researchers analyzed the food diaries of 112 overweight or obese adults with an average age of about 53, who had enrolled in a structured behavioral weight loss program.
All study participants were asked to track everything they consumed each day and their weigh-ins through a mobile app.
Researchers analyzed the participants’ data in two ways. One, in looking at how much each participant’s caloric intake changed each day, and second, how often they logged the same meals and foods each day.
At the study’s conclusion, scientists found that participants with greater consistency in their daily caloric intake achieved better weight loss. For every 100-calorie increase in daily fluctuation, researchers found, a participant’s weight loss decreased by about 0.6% over the study period.
“This means that a person eating the same number of calories every day (1,800) would be expected to lose about 0.6% more of their body weight during the study than a person whose calorie intake would vary from +/-100 calories from their mean (for example, 1,700 some days, 1,900 other days) For a 200-pound person, this is a difference of about 1.2 pounds.”
— Charlotte Hagerman, PhD
“If we were to extend this into 500-calorie deviations (e.g., 1,500 calories on some days, 2,500 calories on other days), the expected difference would be around 3%, or about 6 pounds for a 200-pound person,” Hagerman explained.
When looking at the frequency of foods and meals throughout the week, Hagerman said that study participants who kept more than 50% of the same foods on repeat lost an average of 5.9% of their body weight, compared to only a 4.3% loss for participants who ate a more varied diet. For a 200 lb person, she explained, that would be a difference between about 11.8 lbs compared to 8.6 lbs of weight loss.
Additionally, researchers discovered that study participants who logged more calories on the weekends than on the weekdays also tended to lose more weight.
“The conventional wisdom around dieting says that you should incorporate a lot of different foods to avoid getting bored and that you should splurge on the weekends or special occasions so that you don’t feel as deprived. However, this contradicts research showing that consistency makes your behavior more habitual (that is, more automatic/effortless). We wanted to formally test these competing ideas in a group of people trying to lose weight.”
— Charlotte Hagerman, PhD
“I am hoping to design and test a behavioral program that helps people develop routines around eating, such as forming and relying on a small rotation of meals and snacks, maintaining a stable calorie intake, and eating around the same times every day,” Hagerman said. “I hope to also incorporate routines for other Health behaviors, like physical activity and sleep, to improve overall metabolic Health.”
MNT spoke with David Cutler, MD, a board certified family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA, about this study.
Cutler commented that it may sound obvious that keeping a diet diary, narrowing your food choices, and maintaining a consistent calorie intake can improve weight loss success — but now there’s research to back it up.
“Before the rise of GLP-1 medications like semaglutide and
Cutler said the benefits of a diet diary are substantial.
Benefits of a food diary“There are many excellent, free digital tools available that allow individuals to track calories and better understand their nutritional intake. For this reason, I’ve long encouraged patients to begin their weight loss journey by simply documenting what they eat. At its core, a diet diary promotes mindfulness. When you log your food, you naturally pause to think before eating. Often, that brief moment of awareness is enough to reduce impulsive choices, cut back on junk food, and control portion sizes.”
— David Cutler, MD
“There’s also a built-in ‘accountability effect’ — knowing your habits are being recorded (and potentially shared) can positively influence behavior,” Cutler added. “Additionally, diet tracking is educational, helping individuals better understand the balance of carbohydrates, proteins, and fats in their meals.”
MNT asked Monique Richard, MS, RDN, LDN, a registered dietitian nutritionist and owner of Nutrition-In-Sight, for her top tips on how readers can build sustainable food habits, including creating a rotation of go-to meals and maintaining a steady calorie intake, that may help them lose weight.
“The goal is not to eat the same foods every day, but to create consistent patterns with built-in variety,” Richard explained.
“Keep in mind, being flexible and truly understanding what your body needs and how that translates into foods, meals, and dietary patterns will be something that will save time in the long run and won’t occupy precious real estate in your brain rent-free any longer. What will you do with that space and time?!” she said.
To keep food variety but capitalize on ease, Richard suggested:
- Aim for two to four “go-to” options per meal to help maintain structure without monotony, such as: oatmeal, eggs, or a yogurt bowl for breakfast; a salad, grain bowl, or leftovers for lunch; and stir-fry, sheet-pan meal, or soup for dinner.
- Maintain steady energy intake while rotating foods within groups. For example, Richard said 1 cup of peppers is about equal to 1 cup of cauliflower as they have similar calories, but different flavor and texture profiles.
- Feed microbiome diversity. Richard said that research shows that greater diversity of plant foods supports a healthier gut microbiome.
- Reduce decision fatigue without eliminating choice. Consistency helps, but monotony is not the goal, Richard said, as too much rigidity can backfire.
And Richard advised prioritizing enjoyment and satisfaction.
“When people enjoy their food they’re more likely to stick with it and less likely to overeat later,” she continued. “Pleasure is part of nourishment, not separate from it, and food rules are not welcome at the table. Find a registered dietitian nutritionist (RDN) — an RDN can assist individuals personalize calorie needs, ensure nutrient adequacy, and build sustainable routines without restriction. Consistency is key, but remember that variety is the spice of life!”
