There’s no evidence that P. T. Barnum actually said, “There’s a sucker born every minute.” But if he didn’t say it, he should have, because it’s true—there is a sucker born every minute.

I encounter suckers almost every day in the domain of endurance sports nutrition. Athletes come to me asking why they’ve lost not only weight but also fitness and performance on a ketogenic diet, what I think of intermittent fasting, which antioxidant supplement is best–suckers, all of them!

It’s tough to know whom to blame. On the one hand, I want to blame the suckers. After all, there was a time when I knew nothing about endurance nutrition, yet I never fell for any of the gimmicks being peddled to athletes in those days (we’re talking late 1990s). My instinct was always to take my cues from elite athletes and mainstream science, and both of these sources consistently led me to focus on maintaining a balanced, inclusive diet based on natural, unprocessed foods and to practice a few fine-tuning measures such as eating within an hour after completing big workouts.

Twenty years later, not much has changed. As I write these words, the whole world is talking about Eliud Kipchoge’s jaw-dropping marathon world record of 2:01:39. I can assure you that Kipchoge does not follow a ketogenic diet or practice intermittent fasting or take an antioxidant supplement.

Whenever I make this point, some clown counters that Eliud Kipchoge and his ilk are so genetically different from the rest of us and/or train so much more than the rest of us do that we can’t possibly use them as dietary role models. This is nonsense. The relatively few genes that distinguish elite talents from the masses have absolutely nothing to do with how food is digested and metabolized. And as for training, there is very solid evidence that athletes with average talent get the best results when they emulate elite training practices except at a different scale, so why shouldn’t the same be true of diet?

Anyway, a part of me wants to say that athletes should know better than to adopt diets and nutritional practices that are followed by cult-like athletic subcultures rather than world champions and supported by stories of biological plausibility rather than real science. On the other hand, I recognize that in our society athletes and nonathletes alike are systematically trained to reach for dietary gimmicks and magic bullets. So a lot of responsibility falls on the shoulders of those who try to make suckers out of us.

As one whose job is to help athletes perform better through better nutrition, I find it frustrating to know that if I wrote a book with a catchy shtick that either capitalized on or anticipated the next big fad, a book that made huge promises but was filled with bad information, hence sure to yield poor results for most people, I would make a lot more money than I would if I wrote a book that offered athletes solid, proven guidance on how best to eat for health, fitness, and performance. Most people don’t want the truth about diet—they want a miracle.

This is why I have mixed emotions concerning Marni Sumbal’s new book, Essential Sports Nutrition. On the one hand, I think it’s a good book—a credible, comprehensive primer on eating for fitness and performance. On the other hand, for this very reason, I fear that the endurance athlete market will, on the whole, pass it over in favor of The Keto Alternate-Day Starvation Breakthrough!

I knew that I was going to like Sumbal’s offering by Page 2, where I encountered the following paragraph:

Yet many athletes are misled to believe that there’s only one “right” way to eat. I often hear from my athletes that dairy is bad or that sugar is off-limits during competition season. Right now, the current sports nutrition trend is to restrict carbohydrate intake. I tell athletes that being mindful of what you eat is important, but adhering to only one set of sports nutrition principles is short-sighted. Applying a restrictive approach to sports nutrition often ignores long-term health and performance consequences—especially if the diet is seen as a “quick fix” to boost performance or change body composition. In this book, I take a more all-inclusive approach. I’ll give you practical nutrition strategies to help you enhance sports performance, fitness, and long-lasting health.

An on the very next page, this:

Eating should never cause anxiety, worry, or frustration.

Can I get an amen?

The book is divided into four sections. In the first, Sumbal provides a basic (for many, remedial) education on human nutrition. Part Two focuses on matters of nutrition timing, such as eating for post-exercise recovery. The next section comprises seven chapters aimed at special populations within the broader athlete community, such as children and those pursuing weight loss. Finally, Part Four presents recipes for pre-exercise, during exercise, post-exercise, and non-exercise days.

If you want to  avoid being the next endurance athlete suckered into adopting inferior nutritional practices, or if you’re tired of being suckered, read Essential Sports Nutrition. Shtick sells, but if you want to get faster, you need to know what’s true and do what works.