Participants in a self-directed diet program lost significantly more weight by consuming higher amounts of protein and fiber, while adhering to a personalized, flexible eating plan.
Over the course of a 25-month study, the top-performing participants, who made up 41% of the total, lost an average of 12.9% of their body weight by following individualized plans that emphasized nutrition education and sustainable changes.
Effective Dietary Strategies
Participants in a self-directed diet education program who were most successful at losing weight over a 25-month period ate higher amounts of protein and fiber, one study found. Personalization and flexibility were also key to creating programs that dieters could stick to over time.
After one year, the successful dieters (41 percent of participants) had lost 12.9 percent of their body weight, compared with just over 2 percent of their starting weight for the rest of the study sample, according to a paper about the study published in Obesity Science and Practice.
The Individualized Diet Improvement Program
The dieters participated in the Individualized Diet Improvement Program (iDip), which uses data visualization tools and intensive diet education sessions to increase dieters’ knowledge of key nutrients, enabling them to create a personalized, safe and effective weight-loss plan, said Manabu T. Nakamura, professor of nutrition at the University of Illinois at Urbana-Champaign and leader of the research.
“Flexibility and customization are key to creating programs that maximize success for dieters and those who are able to maintain their weight,” Nakamura said. “Sustainable dietary change, which varies from person to person, must be implemented to maintain a healthy weight. The iDip approach allows participants to experiment with different dietary iterations, and the knowledge and skills they develop while losing weight serve as a foundation for sustainable maintenance.”
The pillars of iDip are increasing protein and fiber intake and eating 1,500 calories or less per day.
Data visualization tools and food recommendations
Using the nutritional guidelines from the Institutes of Medicine, the iDip team created a first-of-its-kind, two-dimensional quantitative data visualization tool that plots the protein and fiber densities of foods per calorie and provides a target range for each meal. Starting with the foods they usually ate, dieters created a personalized plan, increasing their protein intake to about 80 grams and their fiber intake to about 20 grams per day.
Correlations between protein, fiber intake and weight loss
By tracking participants’ eating habits and weight using Wi-Fi-connected scales, the team found strong inverse correlations between the percentages of fiber and protein consumed and weight loss among dieters.
“Research strongly suggests that increasing protein and fiber intake while simultaneously reducing calories is necessary to optimize the safety and effectiveness of weight-loss diets,” said first author Mindy H. Lee, a University of Illinois alumna who was then a graduate student and registered dietitian nutritionist for the iDip program.
The role of protein in preserving lean mass
Nakamura said preserving lean mass is very important when losing weight, especially when using weight-loss drugs.
“Injectable weight loss drugs have become increasingly popular recently,” Nakamura said. “However, using these drugs when food intake is severely restricted will result in serious side effects such as muscle and bone loss unless protein intake is increased during weight loss.”
A total of 22 people enrolled in the program completed it, including nine men and 13 women. Most participants were between the ages of 30 and 64. Participants reported having tried to lose weight at least twice before. They also had a variety of comorbidities: 54% had high cholesterol, 50% had bone problems, and 36% had high blood pressure and/or sleep apnea. Additionally, people who followed the diet reported diagnoses of diabetes, nonalcoholic fatty liver disease, cancer, and depression, the study found.
Impact of depression on weight loss
The seven dieters who were diagnosed with depression lost significantly less weight – about 2.4% of their initial weight, compared with people without depression, who lost 8.39% of their initial weight. The team found that weight loss did not differ significantly among participants with other comorbidities, or between younger and older participants, or between men and women.
Body composition analysis showed that people on the diet maintained their lean body mass, losing an average of 15 pounds of fat mass and minimal muscle mass after six months. Among those who lost more than 5 percent of their starting weight, 78 percent of the weight lost was fat, the study found.
Long Term Weight and Fat Loss Results
Overall, participants reduced their body fat, from an average of 90 pounds at the start of the program to 77 pounds after 15 months. Similarly, participants reduced their waist circumference by about 3 inches after six months and a total of 3.5 inches after 15 months, the team found.
By tracking the protein and fiber intake of dieters, the team found a strong correlation between protein and fiber consumption and weight loss at three months and 12 months.
“The strong correlation suggests that participants who were able to develop sustainable dietary changes within the first three months continued to lose weight in subsequent months, while those who had difficulty implementing sustainable eating patterns early on were rarely successful in changing their diets in subsequent months,” Nakamura said.
The team speculated that this correlation might also have been associated with the early weight loss success of some dieters, which may have increased their motivation and adherence to their program.
Reference: “Successful Dietary Changes Correlate with Weight Loss Outcomes in a Novel Dietary Weight Loss Program” by Mindy H. Lee, Annabelle Shaffer, Nouf W. Alfouzan, Catherine C. Applegate, Jennie C. Hsu, John W. Erdman, and Manabu T. Nakamura, May 27, 2024, Obesity: science and practice.
DOI: 10.1002/osp4.764
The study’s co-authors, all from the University of Illinois, were: Dr. Jennie Hsu, clinical professor of nutritional sciences and internist at Carle Illinois College of Medicine; John W. Erdman Jr. Distinguished Professor of Nutrition and Food Science; medical student Annabelle Shaffer; Catherine C. Applegate, postdoctoral researcher at the Beckman Institute for Advanced Science and Technology; and graduate student Nouf W. Alfouzan.
The project was funded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture and the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health.
