Title: Magnitude and attributed reasons for adult weight gain amongst women at increased risk
of breast cancer
Version: 1 Date: 21 Jul 2022
Reviewer's report:
This study was focused on identifying reasons for weight gain during adulthood in women at
increased risk of breast cancer. This is an important area of research for designing effective
intervention studies that can reduce breast cancer risk in high-risk populations. However, I am
not sure how much this study adds to the literature. The identified reasons for weight gain in
adulthood are already well known. This study would have been more informative if low-risk
women had also been included and comparisons were made to try and identify reasons for weight
gain that were unique to high-risk women. This study was also limited by the fact that women
could select multiple reasons for weight gain with no weight given to the amount that each reason
influenced them. Therefore, it is not clear how much new information is gained by this study.
Additional comments for each section are provided below.
Introduction
The introduction would benefit from a sentence and reference supporting that young adulthood
is the main time for weight gain in women, as this is what is stated in the Abstract.
Methods
Was there any overlap in participants across the studies? Please clarify that the study samples
were distinct across the pooled studies.
Lines 106-108 – This sentence is a confusing explaining how annual weight change was
calculated. Was annual weight change calculated by dividing adult weight gain by number of
years between young adulthood (age 18 or 20) and study entry? Please clarify.
If multiple reasons for weight gain were selected, were women asked to rank their order of
importance? If not, a limitation that should be discussed is that all reported reasons were given
equal weight, which might not accurately reflect how much each reported reason influenced
weight gain.
State which model was used to calculate lifetime risk for the >= 17% inclusion cut point.
Table 2 – what does Risk (1 in x) mean?
This analysis would have been more informative if you compared if reasons differed between
high-risk vs. lower-risk women. Why not include all women from the trials and look at
differences between these groups to see if there are differences that are specific to high-risk
women? The reasons that were revealed in this study are already well known, and so what would
be an addition to the literature is to see if there are differences that are unique to high-risk women.
When I read the Abstract, I thought the paper was focused on reasons for weight gain in young
adulthood, but then the analysis is really focused on weight gain throughout adulthood including
in middle adulthood – such as taking HRT for menopause. Were you able to specifically look
at reasons for weight gain in young adulthood between ages 18-35 years?
The Tables are quite long – maybe collapse some of the reasons with few counts to an “Other
category” and then just include which reasons were included in the other category (for example
those < 5 responses) in the footnote.
Why not do statistical tests to formally test whether there were differences between groups (e.g.,
between moderate vs. high-risk groups)?
Discussion
The Discussion should focus on the fact that the reasons for weight gain in high-risk women
is the same as in the general population. It is not clear to me what new information is gained
from this study. Please use the Discussion to really emphasize what is novel and new about
these findings.