This is a problem. No study should be male only. It creates a gender bias in scientific evidence:
There are metabolic difference between males and females.
It's not a problem, it's just incomplete. From what I've seen, most studies (especially with animals) start out with only male participants, to eliminate the effect of menstruation and the related hormones, which we've seen can be very potent.
This makes it easier on the researchers trying to conduct a preliminary study. The limitations of the study just mean we can't necessarily generalize the results to both men and women, people of different weights, (nor, I suspect, people of various races,) or even, given the sample size, all men of normal weight.
But first we see if we can detect an effect in "normal weight" males, and then we have doubts about its applicability in other populations we test those populations. This of course isn't the most thorough way of experimentation, but it's the biggest bang for your buck when your resources and/or available subject pool are limited.
Actually it's better to have the data separated (or parameterized by gender). Just dont take the advice of a male only study/data if you're not male.
This also applies to genetic/racial background which is particularly challenging due to non-binary nature (eg, what percent irish are you? I bet its >0)
It's a result specific to males. That's not inherently bad. Studies are easier to do with variables like that limited, and a higher sample size of clearer data can be better than 20 people broken down into 5 men, 5 women, 5 kids..
The sample has serious flaws and is quite unrepresentative of the population:
>We examined a group of 16 healthy young men (age 23.6 ± 2.3 years) with a normal body mass index (22.5 ± 1.1 kg/m2)
Size, demographic, gender, and BMI are all seemingly within the same cohort. I have seen neurological studies with an n=8 be the predicates of clinical practice because that's what the patient population on the East coast is, but this could have been expanded.
When looking at the results section, it looks like the data lines up almost inversely. Where if you have a high calorie meal in the morning you'll burn more calories throughout the day whereas eating at night you'll burn more calories at night. But they didn't measure calorie consumption from 23:00 to 7:00 so we have no idea what the measured consumption is.
Maybe I'm naive, but every time I talk to one of my colleagues with a PhD in nutrition they constantly say the same recommendations: eat a diverse diet free of sugar, try to avoid salt and red meat, and get your fiber. Meal timing has been shown to be more for the mind that for your health, in that it doesn't matter when you eat, how much you eat, but you eat correctly. I'll get off my soap box now.
