Meta-Analysis: Weight loss requires >150 minutes per week of aerobic exercise

I was 240 pounds and dropped to 190 pounds in one year. I didn't do any more or less aerobic exercise than I had before my weight loss (which wasn't much). All I did was monitor my weight and adjust my calorie intake to maintain a one pound per week loss. After I completed this diet, not only had I developed better eating habits, I maintained that weight for 10 years. It was only when I caught COVID when my weight quickly rose and I started dealing with chronic health issues that made it difficult to maintain that discipline.

Which is all to say, aerobic exercise is not a _requirement_. I'm sure it works (while maintaining the same calorie intake) and is overall better for your health, but there are plenty of examples of successful weight-loss that don't include lots of exercise.

I was 140kg (310lbs) at some point and got down to 75kg (165lbs) in 1 year. Never did a minute of exercise. I just started eating ~1200 calories per day.

Now, that was 10 years ago, I slowly gained weight again but not to the same degree.

I started the same diet a month ago, at the age of 40, I can not lose weight this time. It is really interesting, I just get exhausted. It's like my body decided not to burn fat but simply shut some stuff down instead. Had some blood tests and stuff and there are no glaring issues.

I guess this time I need to exercise. I wonder if it is age or something else entirely.

There are great many benefits of aerobic exercise (cognition, heart) but using >150min regime as a weight loss tool seems like not the easiest option [so much so that it is almost misleading]. Small caloric deficit (kitchen) + resistance training (to avoid skinny-fat) could be used instead.

I have been trying to get in better shape and lose some weight over the past six months, and what helped me a lot was getting a Fitbit and having a minimum number of “zone minutes” per weekday. I started off at just 22, but I increased it a few minutes every month. Most days I end up doing more than that, but that’s the absolute minimum, but I’ve hit it every weekday for six months excepting a week where I was sick. I do different things different days, so it’s nice to have a consistent metric across all activities that I’m shooting for.

I recently switched to a Garmin watch for a number of reasons, and you can make it track these in this way if you do some customization, but unfortunately the defaults out of the box don’t really support what I got from the Fitbit. I’d really recommend a Fitbit, focusing on zone minutes for anyone getting started on getting in shape.

Why is it not just a correlation? The sort of person who is motivated enough to do exercise is surely likely to also put more effort into what and how they eat. How could you even analyse for causation from a meta-analysis?

Yet they are strongly suggesting causation:

  Meaning: These results suggest that aerobic exercise training at least 150 minutes per week at moderate intensity or higher may be needed to achieve clinically important reductions in waist circumference and measures of body fat.

When examining studies of 8 weeks minimum they needed .5kgs of weight loss per week for the amount lost to be considered clinically relevant.. This sounds like an explanation of the mathematics of the rule system experts have agreed on to define clinically relevant amount of weight loss.

I would presume a metastudy of studies that averages twice as long would show half the amount of exercise needed per week for clinical relevance.

One key note from the study is that they were looking at overweight and obsese people, not healthy people:

> Therefore, our aim was to perform a systematic review and meta-analysis of randomized clinical trials to investigate the possible dose-response association of aerobic exercise of varying intensity with measures of body weight, waist size, and fat in adults with overweight or obesity.