Study design
The participants were randomly assigned to consume a balanced diet
containing 30 g/day brown milled flaxseed (flaxseed group: n=30) or 30
g/day raw milled rice (control group: n=30) for 12 weeks. Random
allocation was performed using blocked randomization method. The study
participants, investigators, and outcome assessors were blinded to the
type of interventions into which the individuals were allocated. The
shape, color, and texture of milled rice were similar to the flaxseed
product. For this purpose, we added edible colors to milled rice at the
laboratory of pharmacy in Shiraz University of Medical Sciences. Calorie
requirement of each subject was estimated using the estimated energy
requirement (EER) equation (32). All
diets consisted of 55% carbohydrates, 18% proteins, and 27% fats.
Also, we provided a portion-size descriptive booklet of common foods for
each participant. All the brown flaxseed products were purchased from
registered herb provider Maleki Commercial Co. (Iran) and stored in a
cool, dark, and dry place. They were milled within a week before
delivery to the patients. Participants were asked to mix the powder with
their dessert or daily meals (e.g., yogurt, salads, and soup) preferably
for lunch. Moreover, participants were advised to maintain their usual
physical activity during the intervention.
To assess the participants’ adherence to the intervention, we asked them
to bring back any unused flaxseed/placebo at each follow-up visit, so
the investigators can estimate their adherence to supplementation during
the study period. Participants were excluded if they consumed less than
90% of flaxseed/placebo. Follow-up assessments were done every 4 weeks
(on 4th, 8th, and 12th weeks) in which participants were provided with
enough supplement for the next four weeks. All measurements including
anthropometric indices, blood levels of lipid profiles, leptin,
adiponectin as well as dietary intakes and physical activities were
performed at the baseline and at the end of the study (week 12).