The idea behind most diets is totally stupid
"Watch your portions and don't eat too much processed food" may be tried-and-true, but it won't lead to instant or drastic results, and it won't make anyone rich. It's much easier to, say, just cut out this ONE EVIL THING - saturated fat, sugar, gluten ... whatever the maligned food of the moment is.
The truth is that there's a disconnect; foods are not bogeymen. Eating too much is bad, and eating too much from a particular food group is often bad.
"What's getting harder to justify, though," writes Aaron E. Carroll, a physician and columnist for The Upshot at The New York Times, "is a focus on any one nutrient as a culprit for everyone."
Anyone can cherry-pick nutrition studies to suit a particular agenda. Yet while "we seek a singular nutritional guilty party," Carroll writes, the real problem is quite simple: "We eat more calories than we need."
That's why it shouldn't be surprising that reducing calories, however you choose to do that, is a pretty effective weight loss strategy. Last year, a major analysis of a wide variety of diets found that they all worked, at least to some extent. The diets were all different - some low-carb, some low-fat, etc. - but they had one thing in common: lower calories.
In other words, most diets tell you to eat less of one thing - but it's a ruse. The real goal here is just eating less, period. Cutting one thing out may help you do that in the short-term, but that doesn't mean that thing is inherently bad.
Still, some eating plans are easier than others. Extreme regimens that cut out a whole food group are often hard to stick to. And that's what you really need to figure out if you're trying to eat better: not which nutrient is the enemy (spoiler alert: none are), but how you can eat healthily over the long-term, not for just a month or a year.
"What isn't helpful is picking a nutritional culprit of bad health and proclaiming that everyone else is eating wrong," Carroll writes. "The best diet is the one that you're likely to keep."