I find Cochrane reviews to generally be of good quality, even if that means there findings are very often “we have reviewed all available data as of X year and we not able to draw any clear findings”. Depending on your technical knowledge it might be useful to point out that they generally include a “plain language summary”.
It is important to note that not everyone agrees with their findings (the abstract of https://pubmed.ncbi.nlm.nih.gov/16052203/ is well worth reading, not just as a criticism of Cochrane but as a comment of the field of research in general). I suppose one could reasonably argue that a combining a load of crap observational or small RTCs (with high drop out / low protocol adherence) is not going to teach you very much, yet this is what systematic reviews of the field tend to do.
You do occasionally see nice articles like https://pubmed.ncbi.nlm.nih.gov/32144378/ which follow 142 people for 2 years. It’s still not a lot of people and not that long to draw conclusions for many different lifestyles and cultures across the entire human lifespan and across the world.
Or see this almost comical example, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7427685/ “12,133 records identified, 30 studies met inclusion criteria … despite the large number of trials included in the review … evidence for primary prevention on clinical endpoints is limited to one large trial with methodological issues … [hence] there is still uncertainty regarding the effects of a Mediterranean-style diet on clinical endpoints and cardiovascular disease (CVD)”
I also second peoples point about examine.com—it’s good.
Also, it’s not really directly answering the question but I want to rant. Calories-in must equal calories-out but in a way that has so many caveats that it’s not really a useful measure of anything.
Processing: A tree, if put in a calorimeter will tell you it has a lot of calories (350 Kcal per 100g for red oak), but if you eat wood, you will shit out wood, we cannot process lignin so cannot extract the calories. Potatoes are interesting, because uncooked, most people (I think this varies by person) cannot process the calories nearly as well, hence the same potato has a different amount of energy depending on how you cook it. Peanuts are calorie dense, but unless you really chew them into a paste (which most people don’t) then you will not be extracting the full calories, hence grinding peanuts into peanut butter increases the effective calories. In short the calories you extract depends on whether you can digest the food, which partly depends on how you prepare it (and partly depends on what species of animal you are and partly on your gut microbiome).
Set point theory (https://pubmed.ncbi.nlm.nih.gov/30026913/) If you exercise more you will want to rest more and you will want to eat more. So if you burn off 100 calories more than you usually do then you might lower your energy expenditure in other ways to make up for it. Or you might eat more than you usually would. A similar thing is probably true if you change the amount you eat- if you eat more you might expend more energy (I know there are studies on this, I was asked to be part of one where I would have to eat and extra 50% calories per day, but I haven’t read the studies). The way these interact is complex and there isn’t a whole load of agreement on what is going on.
I find Cochrane reviews to generally be of good quality, even if that means there findings are very often “we have reviewed all available data as of X year and we not able to draw any clear findings”. Depending on your technical knowledge it might be useful to point out that they generally include a “plain language summary”.
It is important to note that not everyone agrees with their findings (the abstract of https://pubmed.ncbi.nlm.nih.gov/16052203/ is well worth reading, not just as a criticism of Cochrane but as a comment of the field of research in general). I suppose one could reasonably argue that a combining a load of crap observational or small RTCs (with high drop out / low protocol adherence) is not going to teach you very much, yet this is what systematic reviews of the field tend to do.
You do occasionally see nice articles like https://pubmed.ncbi.nlm.nih.gov/32144378/ which follow 142 people for 2 years. It’s still not a lot of people and not that long to draw conclusions for many different lifestyles and cultures across the entire human lifespan and across the world.
See https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD002128.pub4/full for an example of a Cochrane review, and for a list of advice see https://nutrition.cochrane.org/evidence
Or see this almost comical example, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7427685/ “12,133 records identified, 30 studies met inclusion criteria … despite the large number of trials included in the review … evidence for primary prevention on clinical endpoints is limited to one large trial with methodological issues … [hence] there is still uncertainty regarding the effects of a Mediterranean-style diet on clinical endpoints and cardiovascular disease (CVD)”
I also second peoples point about examine.com—it’s good.
Also, it’s not really directly answering the question but I want to rant. Calories-in must equal calories-out but in a way that has so many caveats that it’s not really a useful measure of anything.
Processing: A tree, if put in a calorimeter will tell you it has a lot of calories (350 Kcal per 100g for red oak), but if you eat wood, you will shit out wood, we cannot process lignin so cannot extract the calories. Potatoes are interesting, because uncooked, most people (I think this varies by person) cannot process the calories nearly as well, hence the same potato has a different amount of energy depending on how you cook it. Peanuts are calorie dense, but unless you really chew them into a paste (which most people don’t) then you will not be extracting the full calories, hence grinding peanuts into peanut butter increases the effective calories. In short the calories you extract depends on whether you can digest the food, which partly depends on how you prepare it (and partly depends on what species of animal you are and partly on your gut microbiome).
Set point theory (https://pubmed.ncbi.nlm.nih.gov/30026913/) If you exercise more you will want to rest more and you will want to eat more. So if you burn off 100 calories more than you usually do then you might lower your energy expenditure in other ways to make up for it. Or you might eat more than you usually would. A similar thing is probably true if you change the amount you eat- if you eat more you might expend more energy (I know there are studies on this, I was asked to be part of one where I would have to eat and extra 50% calories per day, but I haven’t read the studies). The way these interact is complex and there isn’t a whole load of agreement on what is going on.