First, the obligatory picture of Hannah Spearritt :-)
women produce more DHA than men.
Why should having higher body-fat percentages make a difference to weight loss? See What is the required energy deficit per unit weight loss? The energy deficit required to lose 1lb of body-weight increases with increasing body-fat percentage. It's rarely 3,500kcals per lb.
If you really love mathematics, see The Dynamics of Human Body Weight Change by Carson C. Chow and Kevin D. Hall.
From the above paper:- ΔU = ΔQ - ΔW
where ΔU is the change in stored energy in the body, ΔQ is a change in energy input or intake, and ΔW is a change in energy output or expenditure. This is the Energy Balance Equation. As I said back in Back to black, CIAB, pharmaceutical drug deficiencies & nerds.
Where body weight is concerned, calories count (but don't bother trying to count them).
Where body composition is concerned, partitioning counts.
Where health is concerned, macronutrient ratios, EFAs, minerals, vitamins & lifestyles count.
N.B. Poor health can adversely affect body weight and/or body
composition, by increasing appetite and/or by adversely affecting