Low in Added Fat
- For millions of years, we may have evolved getting approximately 10 percent of our calories from fat.
There was no butter or oil, nuts were trapped inside hard shells, and animals hadn’t yet been bred to be extra juicy.
- The flesh of some wild game, like moose and elk, is less than 2 percent fat by weight and less than 15 percent calories from fat.
- Even the “lean” ground beef of today can have nearly half of its calories from fat. What about “extra lean”? That comes in at 28 percent fat calories,1400 which is about double that of the extra, extra, extra lean meat of many wild animals eaten by our ancestors.
Resting Metabolic Rate:
- How many calories we burn every hour just to keep our hearts pumping and everything working. 60-70% of RMR. This is called Basal Metabolic Rate (BMR)
- Movement : 20-30%
- Final 10 percent is the thermic effect of food, meaning the calories it takes for us to digest what we consume.
- Interestingly, what we eat not only constitutes calories in but also can affect all three of these dimensions of calories out.
Muscles impacts RMR. More muscles higher RMR
FOOD FOR THOUGHT The take-home message is to cut down on fatty meats and dairy, fried foods, greasy snacks like corn chips, and added oils.
Low in Added Sugar
Why we eat Sugar
- Millions of years of evolution have genetically hardwired us with both an innate liking of the sweet taste of ripe fruit and a sugar-induced subversion of some of our satiety mechanisms.
- When we eat, desire for salty, fatty, and savory tastes diminishes as we slake our hunger, whereas our desire for sweetness is maintained.This makes sense. Because fruit is sporadic and seasonal, an overfeeding response upon discovering a berry bush would have triggered our hunter-gatherer ancestors to eat as much as possible to store energy for later.
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This may explain why we seem to grow a “second stomach” when it comes to dessert. Children may be especially vulnerable since they have a stronger preference for sweet foods than adults, and repeated exposures to sugary foods may accustom young children to a lifelong habit of consuming overly sweet foods.
- Evidence supports the thinking that we don’t just overeat sugar because we like its sweet taste.As I note in the Low in Addictive Foods section, innovations in brain scanning technology have shown that the pleasure-generating reward circuitry in our brains overlaps with the neurocircuitry that mediates the addictive properties of drugs like alcohol and opioids.
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Sugar consumption has also been shown to inhibit anxiety-induced cortisol (stress hormone) secretion, helping to explain why many “comfort foods” are high in sugar and also why excessive sugar consumption may be such a difficult habit to break.
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TAKEAWAY :
- Note that none of these recommendations to cut down on added sugars applies to fruit. As you’ll read in the Rich in Fruits and Vegetables section, fruit can actually facilitate weight loss.
- If you randomize people to a diet low in all sugars, even the naturally occurring sugars in fruit, they do worse than those randomized to just cut down added sugars. Those who retained fruit in their diets lost nearly 50 percent more weight.
Low in Addictive Foods
- Food tastes good for the same reason sex feels good. We wouldn’t last very long as a species without both. Without pleasure centers and reward pathways in our brains incentivizing our efforts, we might not have sufficient drive to seek out either.
- Hunting and gathering take a lot of work. No surprise, then, that our appetites and food cravings are governed in part by the “feel good” messengers in our brains: dopamine (the “reward hormone”), serotonin (the “happiness hormone”), oxytocin (the “love hormone”),endorphins (our own body’s natural opioids), and endocannabinoids (our bodies’ natural cannabis compounds—think of the “munchies” effect).
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Dopamine release is such an important motivator of food intake that animals genetically engineered to be unable to make dopamine simply starve themselves to death.1601 Food just doesn’t seem to do much for them. Too much dopamine release, however, may lead to overeating.
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Researchers found that when rats were allowed to choose between sugar-sweetened water or intravenous cocaine, nine out of ten chose the sweet taste over one of our most addictive drugs.
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In nature, while there are foods that contain sugar (like fruit) and foods that contain fat (like nuts), sugar and fat rarely occur in the same food naturally. There is one, and it’s the most natural food of all. Can you think of it? Breast milk. Maybe that’s why high-fat, high-sugar foods are so addictive. We wouldn’t last long as a species if babies didn’t crave breast milk. Some have speculated that much of the success of both low-fat and low-carb diets may be from the elimination of these high-fat, high-sugar mixtures that we’re programmed to crave.
- Food Addiction also depends on dosage
- Why don’t we crave trail mix as much?That’s about as sugary and fatty as natural foods get. The key appears to lie in the processing, which increases the dose and speed of absorption of the sugar and fat.
- Hard liquor is more addictive than beer because of the dose, and crack is more addictive than cocaine because of the speed of absorption.
- Food processing can increase both simultaneously, delivering high loads of concentrated sugar and fat, while, at the same time, stripping away fiber, protein, and water to maximize the rate of absorption.
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Caffeine has a well-known reinforcing effect. It creates a Pavlovian connection between whatever behaviors the body associates with it, from experimentally conditioning one’s choice of color-coded capsules to changing flavor preferences.No wonder the food industry started adding caffeine not just to soda but to everything from ice cream and candy bars to beef jerky and potato chips. Even bottled water and instant oatmeal have been spiked.
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Surprisingly, we can change our sixth sense too. You’ve probably heard of the five basic tastes: sweet, sour, bitter, salty, and savory. It turns out there are indications our taste buds can register the taste of fat as well. This may help explain why people on low-fat diets start liking low-fat foods more and high-fat foods less. The less fat we eat, the more sensitive to fat our tongues appear to become, which may translate into people spontaneously reducing their intakes of butter, meat, dairy, and eggs. Salt may override this effect, though, so it may be important to cut down on both simultaneously. It’s all about resetting our taste thermostats.
- The average life span of a taste bud cell may only be about 250 hours.That means each of our taste buds could get replaced every ten days or so. This makes sense since they are constantly being assaulted by everything from burning-hot liquids to normal everyday abrasion by our teeth, food, and the roofs of our mouths. Though much of the change in taste perceptions is presumably higher up in our brains, it may be helpful to reflect that our taste buds are basically reborn anew every few weeks, giving us another chance for a fresh start.
Low in Calorie Density
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Dangling a Carrot The biggest influence on calorie density is not fat but water content.Since water adds weight and bulk without adding calories, the most calorie-dense foods and the most calorie-dense diets tend to be those that are dry.
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Some vegetables, on the other hand, are more than 95 percent water, and, as we saw in the High in Water-Rich Foods section, it’s not just iceberg lettuce. Bamboo shoots, bean sprouts, cucumbers, celery, turnips, cooked napa cabbage, bok choy, summer squash, and zucchini may top out at 95 percent water.They’re basically water in vegetable form. A big bowl of water-rich vegetables is practically just a big bowl of trapped water.
Low in Meat
- Take chicken, for example. In 1896, the USDA determined chicken was about 23 percent protein and less than 2 percent fat by weight,1857 which is even leaner than some wild game like venison.
- Today, with ten times the fat, chicken has 1,000 percent more fat than it did just over a century ago.1859 These days, more than 70 percent of the calories in chicken may come from fat. The birds have been genetically manipulated through selective breeding to contain more fat than protein. Chicken Little has become Chicken Big and may be making us bigger too.
Low in Refined Grains
- The number one source of calories in the U.S. diet is refined grains like white flour, followed by added fats like oils. Then come meat and added sugars. Refined carbs and refined fats make up more than half the American diet.
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Food-wise, grain-based desserts like cakes, cookies, pastries, and pies are our single largest calorie contributor. Second is white bread, followed by soda.For our children and adolescents, it’s the same top three, but with pizza replacing the bread.
- FOOD FOR THOUGHT To remove refined grains from your diet is to remove America’s number one source of calories. Switching to whole grains may help reduce body fat, but there’s an even better swap. See the Wall Off Your Calories section for taking your grain game up a notch and graduate from mere whole grains to intact whole grains, such as oat groats (also known as hull-less or hulled oats).
Intact Grain
- Intact grain refers to grains that are in their original, unprocessed form, meaning they have not been cracked, ground, or milled. They retain all their natural components—bran, germ, and endosperm—just as they grow in nature.
- Brown rice, quinoa, whole barley, farro, spelt berries, whole wheat berries, millet, whole oats (not rolled or cut), rye berries.
- Whole grain, on the other hand, refers to any grain product that still contains all three parts of the grain, but it may be processed (e.g., ground into flour, rolled, or cracked). While whole grains retain their nutrients, their physical structure may be altered.
- Whole wheat flour, whole grain pasta, whole grain bread, rolled oats, steel-cut oats, whole grain crackers.
Low in Salt
- There is one recent human experiment that could provide a mechanism by which salt may contribute to obesity. When people were switched to a low-salt diet, the levels in their blood of the gut hormone ghrelin dropped, and when shifted to a high-salt diet, their ghrelin levels shot up.
- Ghrelin, the so-called hunger hormone I discussed in the High in Fiber-Rich Foods section, is the target of attempts by drug companies to create an anti-obesity vaccine,1928 but we may be able to help block its action naturally by lowering our sodium intake.
Low Insulin Index
- The Hormone of Plenty Insulin can be thought of as the “hormone of calorie prosperity.”
- After a meal, our blood is awash with calories.
- The starches we eat are broken down into simple sugars, the proteins into amino acids, and the fats into fatty acids, all of which are absorbed into our bloodstreams.
- Insulin then goes to work to distribute and store this bounty.
- It moves the blood sugars into our muscles to fuel our movement,
- gets our cells to take up the amino acids to build new proteins, and
- stockpiles circulating fatty acids into our fat stores.
- Insulin drives fat storage both by directing fat from our bloodstreams into our fat cells and by telling our fat cells to stop burning calories. Insulin is, after all, the signal of abundance.
- Note: Insulin acts primarily to stimulate glucose uptake by three tissues—adipose (fat), muscle, and liver—that are important in the metabolism and storage of nutrients.
Obesity and Insulin
- When we consume more calories than our body needs over time, our fat cells (adipocytes) store the excess energy in the form of triglycerides, causing them to expand. However, fat cells have a limit to how much they can store. If we become obese and our fat cells reach their maximum storage capacity, excess fat (in the form of free fatty acids) can start spilling back into the bloodstream.
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Fat in the Bloodstream – The leaked fat circulates in the blood as free fatty acids. Elevated levels of these fatty acids can lead to metabolic issues like insulin resistance.
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Fat in Muscles: – Some of the excess fat gets deposited in muscle tissue. This is called intramuscular fat accumulation
- This interferes with insulin signaling, making muscles less responsive to insulin.
- Normally, our muscles take up blood sugar in response to insulin, but if they become resistant to the effects of insulin, the sugar remains in the blood and can build up to dangerous levels. To prevent this, our bodies produce even more insulin to force more blood sugar into our muscles. But all that extra insulin in our system can cause additional fat storage and result in a vicious cycle: obesity leading to insulin resistance,
- When insulin resistance gets so bad that our insulin production can no longer keep up and overcome it, our blood sugars start creeping up and we become prediabetic and then progress to full-blown diabetes. Instead of treating the cause—insulin resistance—with lifestyle medicine to try to reverse the diabetes, what do most doctors do? Prescribe even more insulin, which can perpetuate the cycle.
- With injections, insulin levels can be forced so high that even resistant muscles will concede, but what effect will all that extra insulin have on our fat stores? Within the first year of starting insulin, type 2 diabetics typically gain between seven and twenty pounds of “insulin-associated weight gain.”
Insulin Resistance Without Obesity
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While obesity is a well-known risk factor for insulin resistance, you don’t need to be overweight to develop it.
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The fat that clogs muscle cells and disrupts insulin function can come from two sources:
- The fat stored in the body (especially if it’s spilling into the bloodstream).
- The fat consumed in the diet, particularly from high-fat meals.
Fat Levels in the Blood: Obese vs. Lean Individuals
- Normally, free fatty acid levels in the bloodstream are around 100 μmol/l.
- In obese individuals, this can rise to 800 μmol/l, due to constant fat overflow from enlarged fat cells.
- However, even a thin person who eats a high-fat, low-carb diet can reach the same 800 μmol/l levels.
- This suggests that excess dietary fat alone—even without obesity—can lead to metabolic dysfunction.
####. Direct Evidence: Fat Infusion Studies
- In controlled studies, researchers have infused fat directly into people’s veins and used MRI scans to track its movement.
- Within hours, fat starts accumulating in muscle cells, impairing insulin function. - The same fat buildup happens when people consume a high-fat diet over time.
- Even a single high-fat meal can significantly reduce insulin sensitivity within six hours.
- This means muscle cells struggle to take up glucose from the blood, forcing the pancreas to produce more insulin to compensate.
- Over time, chronically high insulin levels can promote weight gain, creating a vicious cycle of increasing insulin resistance and fat storage.
The Takeaway
- Insulin resistance isn’t just about being overweight—it’s also about what we eat.
- A high-fat diet can impair insulin function, even in thin individuals.
- Repeated exposure to high-fat meals can set off a cycle of rising insulin resistance, increased insulin levels, and eventual weight gain.
- Managing dietary fat intake, especially from unhealthy sources, is key to preventing insulin resistance.
Summary
- Low in Added Fat:
- Our ancestors consumed only ~10% of calories from fat, whereas modern diets are much higher.
- Fatty meats, dairy, and oils contribute significantly to excess fat intake.
- Reducing added fats can help regulate metabolism and support a healthy weight.
- Low in Added Sugar:
- Sugar triggers brain pathways similar to addictive substances.
- Naturally occurring sugars (like in fruit) are beneficial, while added sugars should be minimized.
- Low in Addictive Foods:
- Processed foods high in fat and sugar are engineered to be addictive.
- The combination of fat and sugar is rare in nature (except for breast milk), which may explain why we crave processed junk food.
- Low in Calorie Density:
- Water-rich foods (vegetables, fruits) provide bulk without excessive calories, promoting satiety.
- Low in Meat:
- Modern meats, especially chicken, have been selectively bred to be high in fat.
- Reducing meat consumption can lower fat intake and improve health.
- Low in Refined Grains:
- Processed grains (white flour, refined carbs) dominate the modern diet.
- Replacing them with intact whole grains (e.g., quinoa, brown rice, oat groats) can improve satiety and metabolic health.
- Low in Salt:
- High salt intake may contribute to hunger and obesity by increasing ghrelin (the hunger hormone).
- Low Insulin Index:
- Insulin regulates fat storage, and high-fat diets contribute to insulin resistance.
- Excess dietary fat, even in lean individuals, can impair insulin function and increase diabetes risk.
Key Takeaways
✅ Reduce fatty meats, dairy, fried foods, and oils to lower dietary fat intake.
✅ Limit added sugars but keep fruits, as they aid in weight loss.
✅ Avoid highly processed foods engineered for overconsumption.
✅ Choose whole, water-rich foods to increase satiety and control calorie intake.
✅ Prioritize intact whole grains over refined grains for better metabolic health.
✅ Reduce salt intake to naturally regulate appetite.
✅ A high-fat diet can cause insulin resistance, even in thin individuals.
✅ A whole-food, plant-based diet can help reverse insulin resistance and promote long-term health.