Diet debates are out of control. The vitriol! The name-calling! I understand how tempers get heated and rhetoric gets out of hand over things like politics and religion, but how did we get to a place where people are vile to other people because they disagree about carbohydrate metabolism?

A lot of people in this space are trying, in good faith, to be helpful, so I would hope we could ratchet down the nastiness. In an effort to spread a little kumbaya, I thought I would try to sketch out areas of agreement, and there are more than you might think. Here, in the interest of peace on Earth, or at least on Twitter, are five (maybe even six) diet-related ideas that everyone agrees on.

But, before I tell you what they are, I have to tell you who, exactly, “everyone” is. It is not literally everyone. There is literally nothing that literally everyone agrees on, up to and including the roundness of Earth. Whatever I put forward as a universal, there will be a rock under which you will find dissenters. Nevertheless, there are many universals that the colloquial “everyone” really does agree on. Everyone within shouting distance of reasonable, everyone who actually knows something about diet and nutrition, everyone who does not live under a rock.

1. You must run a calorie deficit to lose weight.

This isn’t even about diet. It’s about physics. Calories are a unit of energy, and all the energy your body absorbs from food (which isn’t all the energy in food, see No. 3) must either be expended or stored as fat. If you’ve stored more than you would like, and you want to lose some of it, you have to find a way to absorb fewer calories, burn more or both.

2. Telling people that doesn’t help them lose weight.

One argument goes like this: Health authorities have been talking about calorie deficits for decades, yet obesity continues to skyrocket. Ergo, calories-in-calories-out (CICO) is nonsense.

What if it was money instead of calories? You can tell people till you’re blue in the face that, if they want to save money, they have to earn more than they spend. It’s just math. Yet 36 percent of American households report that they would have trouble paying for a $400 emergency.

Does that mean earning more than you spend isn’t the key to accumulating savings? Or does it just mean that earning more than you spend is hard, especially if you’re, say, a single parent with a low-wage job and an ailing father and no health insurance — and you just got a rent increase.

Nobody believes that the math is particularly helpful in either situation, but saying “CICO is debunked!” has led some people to believe that No. 1, above, isn’t true. Magical thinking isn’t helping here.

3. Different foods are metabolized differently, which can affect the calorie equation.

It takes calories to process the food you eat, and each of the macronutrients — fat, carbs, protein — requires a different amount. (Scientists call this the “thermic effect of food” because “digestive overhead” was way too descriptive.) Protein is the hardest for our bodies to break down, and you use 20 to 30 percent of its calories to do the job. Carbohydrates are easier, and require 5 to 10 percent of their calories. Fat is easiest, and requires about 3 percent.

And, of course, not everything you eat is absorbed. Plant foods have fiber and other kinds of compounds that you can’t break down completely, and some of those calories pass right through you.

There’s also some evidence that a very-low-carbohydrate diet may increase energy expenditure (and some that it doesn’t), and the question of whether it’s enough to be meaningful is disputed.

And that’s the key here: The amount of the difference. Yes, you can rejigger your diet to change the calorie equation, but the question is whether you can change it enough so that the difference is effective for weight loss. I am skeptical, simply because so many people have tried so much rejiggering, and we haven’t yet lit on an effective combination.

But one of the great things about weight-loss diets is that they don’t have to work for everyone. They only have to work for you.

4. Cutting refined carbohydrates is an excellent place to start.

While many low-carb advocates believe carbohydrates are uniquely fattening, you don’t have to believe that to think passing on pasta is a good idea. Refined grains — white bread, white rice, pasta — have had most of their nutrition stripped out of them, so all you’re giving up is calories. (Most white flour has had some nutrients put back in, and one of them is folic acid. The only caveat here is that if you’re pregnant or thinking of becoming pregnant, you may want to supplement with folic acid if you’re cutting out fortified white flour.)

For many of us, refined carbs are also diabolically easy to overeat. I hear the siren song of baguettes loud and clear, and once I rip the crusty end off the fresh loaf, it’s all over.

Carbohydrates are also a key element in the delicious carbs/fats combination. There’s some evidence that foods that have both are more appealing to us than foods that are one or the other. If you make a list of foods you tend to overeat, chances are good that a lot of them combine fats and carbohydrates in extremely delicious ways. Cut back on carbs, and you cut back on those.

When my weight creeps up, which it periodically does, refined carbohydrates are the first thing to go. (Besides, if it wasn’t that, it might have to be the wine.)

5. The world should be kind and supportive for everyone, at every weight.

I have fought my weight all my life, and I’m winning now, but I didn’t always. I’ve personally experienced the difference between Existing While Fat and being relatively thin; it is remarkable and it is dismaying. Anyone who has ever been overweight knows how unpleasant a place the world can be, but the unpleasantness has been codified in studies of employment, health care, schools and just plain living.

I think we all want that to stop, although not everyone agrees about how. For some, it means not talking about weight loss at all — and I hear from those people every time I write about it — but I can’t agree. Weight is about the most personal decision going, and yours is nobody else’s business. There are people who are comfortable and happy at a weight classified as obese, and I think that’s totally fine, because being comfortable and happy is more important than losing weight. But there are many others who want to be thinner, and they need support, too.

I’d like to believe in a sixth idea we can all agree on: that nastiness doesn’t make this better. Whether you’re keto or vegan, low-carb or low-fat (and, yes, there are still some of those and it’s okay), congratulations if you’ve found a diet that you enjoy and that helps keep you at the weight you want to be. By all means, share your story, or your theory, or your recipes. But keep in mind that, in studies, no diet works appreciably better than any other in the long term. Although low-carb diets are a bit more successful than others in the short term, by the time you get to two years, what few long-term trials there are show very little weight loss and no more than a few pounds’ worth of difference between diets.

The best evidence for the failure of diets, though, is the trajectory of our collective weight gain, which makes it clear that eating a healthful diet and being the weight you want to be is hard. But having a constructive, respectful conversation about it shouldn’t be. Can’t we dial back the sneering and the smugness, the venom and contempt?

The idea that we should be nice to one another shouldn’t be controversial.

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