Table 1 Rationale for dietary counseling

Baseline visit

Daily energy requirements

Pocket formula [10,11,12] according to the participants’ BMI classification at baseline visit:

• 20 kcal/kg for overweight and obese participants (BMI ≥ 25 kg/m², targeting weight loss);

• 25 kcal/kg for normal BMI participants (BMI 18.5 to 24.9 kg/m², targeting weight maintenance);

• 32 kcal/kg for those with low BMI (BMI < 18.5 kg/m², targeting weight gain).

Baseline visit

Semi-quantitative nutritional counseling

• Dietary counseling to raise awareness of the colored food groups: encourage participants to increase intake of foods in the green group, moderate foods in the yellow group and reduce intake of foods in the blue group in the next 30 days;

• The intake of ultra-processed foods (red group) will be strongly discouraged throughout the trial;

• Participants will receive an educational material with a brochure to aid food choices (according to color groups), and a recipe book (with tested recipes, adapted to the protocol).

Visits 2, 3, and 4

Quantitative nutritional counseling

• Distribution of daily portions of each food group (colors green, yellow, and blue) into the participants’ routine according to the energy requirements planned at baseline visit;

• Use of pre-elaborated menus that balance the amount of green, yellow, and blue food servings (1400 to 2400 kcal) [11] as examples for counseling;

• Encourage patients to make their own combinations using the educational materials supplied, so to achieve the energetic goal established at baseline visit;

Visit 5

Qualitative nutritional counseling

• Make final adjustments to counseling and encourage participants to maintain the new healthy patterns acquired after the study’s finished.