Planning to start a weight loss diet but unsure if it will be effective? Researchers now say success depends on including more protein and fiber while limiting calories. According to a study that tested a new diet program, personalization and flexibility are also key to long-term adherence.

At the University of Illinois, researchers tested a new weight loss program called the Individualized Diet Improvement Program (iDip) which involves increasing protein and fiber intake while consuming 1,500 calories or less daily for one year.

The iDip research team created a unique tool that shows the amount of protein and fiber in foods per calorie and gives a target range for each meal. By using this, the dieters could create an individualized plan, increasing their protein intake to about 80 grams and their fiber intake to about 20 grams daily.

The researchers followed up on the participants' dietary habits and weights using Wi-Fi-enabled scales. Participants who successfully completed the program experienced a 12.9% reduction in body weight. The results showed "strong inverse correlations between the percentages of fiber and protein eaten and dieters' weight loss."

iDip uses data visualization tools and detailed dietary education to help participants understand key nutrients. This allows them to create a personalized, safe, and effective weight-loss plan, according to research leader Manabu T. Nakamura.

"The iDip approach allows participants to experiment with various dietary iterations, and the knowledge and skills they develop while losing weight serve as the foundation for sustainable maintenance. Flexibility and personalization are key in creating programs that optimize dieters' success at losing weight and keeping it off. Sustainable dietary change, which varies from person to person, must be achieved to maintain a healthy weight," T. Nakamura said in a news release.

The study involved 22 participants, including nine men and thirteen women, between the ages of 30-64. Participants had a range of comorbidities such as high cholesterol, skeletal problems, hypertension, diabetes, nonalcoholic fatty liver disease, cancer, and depression.

While analyzing the weight loss across different comorbidities, the researchers made some interesting observations: the participants with depression lost less weight (2.4% of their starting weight) compared to those without depression (8.39%). However, weight loss was similar across other health conditions, ages, and genders.

When the researchers conducted body composition analysis, they noted that participants on iDip lost an average of 7.1 kg of fat while they preserved their lean body mass. Those who lost more than 5% of their body weight had 78% of the weight loss from fat. Overall, fat mass decreased from 42.6 kg to 35.7 kg, and waist size reduced by 7 cm after six months and 9 cm after 15 months.

"The research strongly suggests that increasing protein and fiber intake while simultaneously reducing calories is required to optimize the safety and efficacy of weight loss diets," said Mindy H. Lee, the first author, and registered dietitian-nutritionist for the iDip program.

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