I had the privilege last week to give a talk on weight control to the workforce of the United States House of Representatives.
The gist of it all was- Of course, calories count, but who wants to spend a lifetime counting them? Yes, there is a better way. I told them about it and I’m about to tell you as well.
That calories absolutely count – despite recurring pseudo-scholarly ruminations on the subject – should be irrefutable. The matter is settled independently by simple reason, basic logic and the laws of physics – to say nothing of this trio. The form and function, mass and biochemistry of any organism operate on the energy provided by a given fuel source. Calories quantify this energy in food.
Of course, no given number of calories reliably predicts weight results for all of us, nor does a given number of kilometers predict run time for all of us (some of us can run marathons of 2 hours, most of us can’t) – but a mile is still a mile; neither does gallons of fuel predict how far each car will travel (some cars are very fuel efficient, others are gas guzzlers) – but a gallon is still a gallon; etc. Calories matter, but the nature and quality of the “fuel” calories are also important; So too are the myriad peculiarities of the individual “machine” that these calories power. I have already spent a lot of time on this topic, more than one time– it is fully cooked. It is time to move on.
The number of calories we need to feel full and satisfied – which, presumably, is what we all aim for when we start to eat – is, alas, very vulnerable to manipulation. And manipulated, it is. We have been told the story, more than one time, from scientists working for large food companies, using functional MRI technology to determine which formulations are most likely to put our appetite centers on alert. Remember when they “bet” that we couldn’t eat a single one? The house always wins; and they are home. Their bet was safe and by no means limited to crisps.
Thanks to the revolutionary work of Professor Carlos Monteiro and others, we can now catalog such manipulations of our food using the NOVA processing classification. This, in turn, has enabled researchers who are experts in energy balance, in particular, Kevin Hall at NIH– isolate and evaluate the effects of ultra-treatment. The result is as we all might expect, and what those who devised “addictive junk food” already knew: Ultratransformation, regardless of other considerations, increases the calories we consume. And so, inevitably, also increases our weight, because, in case you missed the memo, calories count.
Reflecting on and struggling against this uneven playing field throughout my career – I have been inclined to equate obesity with drowning. A human body “drowns” not because there is something wrong with the body, but because a perfectly normal and healthy human body, functioning as it should, simply cannot stay under. water too long. We are not fish. Likewise, a perfectly normal and healthy human body cannot cope with an endless stream of willfully over-appetizing calories and labor-saving technology. We can drown in thesebecause we can drown in water. We have been do just that for years and decades. We have powerful adaptations to protect us from hunger; we have adaptations that help us use our muscles as needed to survive. We have no native defense against excess calories and the allure of the couch… having never needed one before; never, therefore, to make them evolve.
What we cannot solve with genetic adaptation, we can solve with ingenuity – the signature attribute of our species. What will the will not do for us- skill just might.
Opposing the pernicious adulterations of the food supply that so effectively undermine our attempts at restriction is the satiety science. Fullness refers to a lasting feeling of fullness and the ability of foods to provide it. The fewer calories needed to achieve fullness, the less we tend to consume. The bigger the number, well, just ask for an empty bag of chips.
A number of factors influence satiety thresholds. Among the best studied is volume; foods that take up a lot of space, especially but not only those that have a low calorie-to-volume ratio, reliably reduce the calories needed to feel full. The most obvious illustration is whole fruits and vegetables, but soups and stews, which distribute calories in greater volume than drier preparations, also express it. Macronutrients may be important, as protein induces more satiety, calorie for calorie, than simple carbohydrates or fat. But this effect seems to be less reliable.
Fiber, which contributes to food volume, can influence satiety via other mechanisms, including the slowed absorption of nutrients from the gastrointestinal tract into the bloodstream. The effects of fiber intake on satiety appear to be quite reliable and robust.
Among the most important influences on satiety is variety. Certain flavors, in particular sweet, and to a lesser extent, salty and savory, stimulate the appetite, and this independently. Combine these flavors in foods and dishes, and more than one “appetite channel” is activated at a time. Have you ever met someone who can avoid overeating at an all-you-can-eat buffet? Me neither. The carefully ultra-processed formulations that inhabit the modern food supply turn many individual foods into an analogue of such a buffet: salt lurks in sugary foods (like breakfast cereals); sugar is hiding in salty foods (including salty snacks); etc. Each of these foods is a real buffet in itself.
The tendency to fill in a flavor-specific way has a name: specific sensory satiety. The tendency to keep eating when the flavors are mixed might simply be called: business as usual. If you’re not entirely convinced, remember a family vacation where you ate until you had trouble breathing and still found room for dessert. Case closed.
What to do with all this?
Make your way to healthy foods in any sensible and balanced combination. In other words: to control the quantity, focus on the overall quality of your food.
Yeah, I know, there’s no pixie dust on it, sorry. It’s simple, obvious, and you might have even heard it before. None of this changes the fact that this is the only real solution. Among the many virtues of healthy foods in their original, minimally processed state is that they fill us with fewer calories. You can control your calorie intake by focusing on quantity and spend the rest of your life heavier or hungrier than you want. Or you can focus on quality – filling up with fewer calories – and getting both lean and full on the same menu.
More good news on this subject: as long as there is a single, well-established basic theme of healthy nutrition for human animal species, there are many reasonable variations on this theme. You can, and in my opinion should, find a way that allows you to love the foods that love you back. Transitioning from an ultra-processed junk food diet usually involves a brief period of papillae rehabilitation– wean your palate from a preference for such junk food and teach it to reward you for eating real food. It works great, happens fairly quickly, and is a very small investment for a lifetime of returns: enjoyment of both good food and good health.
One last thing. The overall quality of the diet is the – yes, “the”, not “a” – leading predictor of premature death and chronic disease in the modern world. Managing calories without worrying about the quality of the diet isn’t just doomed – the forest is missing for a tree. Weight probably matters to you, but so do years of life and life in years, and the quality of your diet is determining, and powerfully, to that extent.
Calories matter, but you have better things to do than count them for the rest of your life. Choose a way of eating that you like and maximize its quality. It is something that each of us can manage for ourselves and our families, in our own home. And the house always wins.