The US food pyramid changed.
Tallow beef fat is now listed as a cooking option, for the first time in more than sixty years.
That headline grabbed attention. People argued about saturated fat. They debated molecules, LDL, and risk ratios.
But the interesting part is what almost everyone missed while they were fighting: the question quietly changed.
The Question Was Broken
For decades, nutrition science obsessed over one question: "What's the best diet?"
That question created tribes of keto evangelists, paleo purists, vegan advocates, Mediterranean devotees, low-fat zealots, and carnivore converts. Each camp had studies, success stories, and before-and-after photos.
Yet while the tribes argued, rates of obesity, type 2 diabetes, and cardiovascular disease kept climbing.
The question generated answers, but none of them solved the problem at scale.
Munger's Inversion, Applied To Food
Charlie Munger built a career by flipping questions.
Instead of asking "How do I succeed?", he asked, "What guarantees failure?" then systematically avoided those things.
Nutrition needs the same inversion.
Stop asking:
"What's the best thing to eat?"
Start asking:
"What reliably makes people sick?"
The One Thing Every Diet That Works Agrees On
Here's the striking part about all those diet tribes: they disagree on almost everything.
Animal versus plant. High carb versus low carb. High fat versus low fat. Meal timing. Fasting. Snacks.
But there is one shared conviction.
Every pattern that consistently improves health does the same thing first: it eliminates ultra-processed foods, added sugar, and refined carbohydrates.
These approaches work less because of what they add and more because of what they remove.
That's the signal. Everything else is noise.
The Upstream Problem We Ignored
For sixty years, official guidance tried to identify which specific foods "cause" disease.
The better question is: "What condition makes the body vulnerable to disease in the first place?"
Research increasingly points to metabolic dysfunction as the upstream problem—particularly insulin resistance and chronic low-grade inflammation.
These aren't just side effects of eating the "wrong" food; they are system-level conditions that change how the body handles any food it receives.
Food does not hit a blank slate. It hits a system that is either metabolically healthy or already damaged.
Reviews in Circulation Research and related journals show that chronic low-grade inflammation is detectable throughout the body in obesity and plays a causal role in insulin resistance and cardiovascular disease.
When insulin sensitivity is intact and inflammation is low, the body handles saturated fat and cholesterol through well-regulated pathways.
When the system is already inflamed and insulin resistant, the same plate of food can push things further off the rails.
For sixty years, we blamed the food. We largely ignored the condition of the system processing it.
The Vicious Cycle
Here's how the metabolic loop is described in the research:
Chronic inflammation interferes with insulin receptors, so cells become less responsive to insulin.
Glucose stays elevated; the pancreas compensates by pumping out more insulin.
Chronically high insulin promotes fat storage, especially around the organs.
Those fat cells release inflammatory molecules (like TNF-α and IL-6), which further damage insulin signalling.
More fat → more inflammation → worse insulin resistance → more fat storage.
The system feeds on itself.
That is why simple calorie restriction so often fails long-term: it tweaks the input without fixing the system.
And it is why removing ultra-processed foods works across wildly different diets; those foods simultaneously spike blood sugar, promote inflammation, and make overeating effortless.
Cut them out and you interrupt the cycle at multiple points.
The Saturated Fat Question (And Its Trap)
Now the new guidelines get interesting—and a little contradictory.
They encourage protein from animal foods, include full-fat dairy, and even list butter and beef tallow as preferred cooking fats, while still advising that saturated fat stay under 10% of daily calories.
Harvard's nutrition analysts, the American Heart Association, and other groups have already highlighted how difficult it is to follow those food-based recommendations and still stay under that cap.
You can feel the tension: "Use tallow and full-fat dairy, but also, don't let saturated fat exceed 10%."
It's not a coherent message.
That confusion comes from asking the wrong question: "Is saturated fat bad?"
Better questions look like this:
What kind of saturated fat?
Different fatty acids behave differently. Stearic acid, which makes up a substantial portion of beef fat, has been shown to have a neutral effect on total and LDL cholesterol compared with other saturated fats.
What replaces it?
Swapping saturated fat for refined carbohydrates and added sugars does not improve cardiovascular outcomes and can worsen metabolic markers, in part by driving the liver to create its own saturated fats.
What's the metabolic state of the person eating it?
Studies of acute saturated fat loads show transient drops in insulin sensitivity, but lean, metabolically healthy individuals compensate effectively, whereas those already insulin resistant may not.
The context, not the isolated nutrient, determines the risk.
What You Eat With Saturated Fat Matters
Saturated fat is not a food; it is a component inside foods.
When it comes embedded in whole foods—grass-fed beef, lamb, eggs, or full-fat dairy—it arrives alongside protein, micronutrients, and other fats that carry their own benefits.
When saturated fat shows up in ultra-processed foods, it's packaged with refined starches, seed oils, flavour enhancers, and sugar at levels no traditional kitchen would ever combine.
That combination—saturated fat plus refined carbohydrates plus sugar—is what drives repeated glucose spikes, chronic inflammation, and effortless overconsumption.
One picture:
Steak with mushrooms and seasonal vegetables cooked in tallow.
Another picture:
Steak with fries, a sugary drink, and dessert fried in industrial seed oil.
Same saturated fat source; radically different metabolic implications, especially over years.
If your diet is heavy in sugar and refined starch, loading in more saturated fat is probably a bad idea.
If your diet is built on whole foods and keeps sugar and refined starch low, the saturated fat that naturally comes with those foods is unlikely to be the main problem.
A Simple Framework For Real Life
When the dust settles, here is the order that actually matters:
1 Remove what reliably harms
Ultra-processed foods, added sugars, and refined carbohydrates are the common denominator across every successful dietary pattern and are now explicitly called out as categories to limit or avoid in the new guidelines.
2 Add what supports the function
Prioritise protein, micronutrient-dense foods, fibre, and naturally occurring fats that carry fat-soluble vitamins A, D, E, and K—which require dietary fat for absorption.
3 Personalise based on your response
Use your genetics, blood work, metabolic markers, energy levels, and performance to fine-tune the details. The pyramid gives population-level guidance; your body provides the real-time feedback.
Tallow fits into this framework as a whole-food fat from a single, recognisable ingredient.
When it replaces ultra-processed frying oils and is used with real food—meat, vegetables, eggs—it supports the shift away from the very foods the guidelines finally name as the problem.
The Real Shift (And The Opportunity)
The new guidelines did not end the "war on saturated fat"; the 10% cap is still there.
But they did something more important: they finally named ultra-processed food as a category to limit, and they brought traditional fats like butter and beef tallow back into the conversation as legitimate cooking options.
That's the door opening.
The base pattern is clear: eat mostly whole foods, hit your protein, use real fats, keep processed junk rare.
From there, it becomes individual. You test. You measure. You notice how you feel, how you perform, how your health markers move.
Munger's inversion still applies: figure out what reliably guarantees failure—metabolic dysfunction fuelled by ultra-processed food—and avoid that first.
Then choose the specific version of whole-food eating that works best for your life, your family, and your kitchen.
For many people, that now includes a jar of Tasmanian grass-fed tallow on the bench—quietly doing its job while the debate rages on.
References
[1] U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2025-2030. January 2026.
[2] Li C, et al. "Metabolic Inflammation and Insulin Resistance in Obesity." Circulation Research. 2020;126:1549-1564.
[3] Li M, et al. "The crucial role of insulin resistance in metabolic disease." Frontiers in Endocrinology. March 2023.
[4] Harvard T.H. Chan School of Public Health. "Dietary Guidelines 2025-2030 Analysis." The Nutrition Source. January 2026.
[5] Grundy SM. "Influence of stearic acid on cholesterol metabolism." American Journal of Clinical Nutrition. 1994;60(6):986S-990S.
[6] von Frankenberg AD, et al. "High-fat diet and insulin sensitivity." European Journal of Nutrition. 2017;56(1):431-443.
[7] Vessby B, et al. "The KANWU Study." Diabetologia. 2001;44(3):312-319.
[8] Hernandez EA, et al. "Acute dietary fat and insulin resistance." Journal of Clinical Investigation. 2017;127(2):695-708.