Eating more carbs won’t necessarily increase inflammation. Being FAT does necessarily increase inflammation because the more stored body fat you have (even fatty acids stored in muscle cells for energy) the more insulin you need to manage a given number of carbs.
That doesn’t mean that eating fat increases inflammation, but getting fat from eating fat will raise insulin needs just as getting fat from eating carbs will.
So, carbs and fat both raise insulin needs, and quite comparably in the long run. Studies done (including my own with my son) with type 1 diabetics show that when one raises carbs from 25% to 75% of daily calories, as long as they are low inflammatory carbs (I’ll get to that later) and calories are held constant at a maintenance level only increases total daily insulin needs by 30-50% (so increasing carbs to 300% only increases insulin needs to 130-150%). The reason is that on a higher fat diet, the body gets better at mobilizing fatty acids, moving them into cells and using them for energy, and it reduces its rate of using, and storing glycogen in muscles for fuel.
Anyway, this is important because insulin IS inflammatory, by definition.
The “blood sugar” advantage of higher fat diets (again as long as someone is not overeating), is that it lowers the peaks and raises the valleys. People who live on carbs will usually go higher at their peak, but they will also go lower 3-4 hours after eating if they don’t eat again. This causes swings that are great enough to cause harm. Blood sugar swings are more damaging to eyes, kidneys and blood vessels than merely having high blood sugar because cells swell and crenate when they experience changes from high to low or low to high as they attempt to move water in and out to maintain osmolarity.
So someone who eats high carbs, especially fast carbs, without much fat may see their blood sugar range from 60-140 over the course of a day, while someone who eats more fat and fewer carbs may see a range of 80-120, meaning a) less swelling and shriveling of cells that can be easily damaged, and less hunger/better appetite control.
If someone ate carbs that are fast, like potato and rice and glucose polymer containing drinks and some fruit, they could manage this by eating more frequently, but smaller portions of carbs, say 50 grams 6 times per day rather than 75-150 grams 3 times per day. This would prevent as high rises, prevent insulin over secretion which leads to crashes. Solution 1 is to eat “faster” carbs in smaller, but more frequent feedings, or to eat them during exertion (though weight training may actually raise spikes and make lows even lower because it stimulates stress hormones and it raises insulin sensitivity later. Solution 2 is to combine them with fat, and reduce the carb content to stabilize blood sugar.
Solution 3 would be to eat “low GI” carbs. These would, in theory not spike blood sugar as much, and not lead to low blood sugar rebounds. The problem is that low GI carbs like whole wheat, and legumes ARE low GI because they contain inflammatory gut irritants that slow down digestion and absorption by distressing the gut to some degree. These include lignins, lectins, and allergenic proteins like-but not limited to-gluten. The other low GI option is to eat more fruit which is lower GI because it is half fructose (which is slower absorbed and turned into glucose) and also because fruit contains acids and fiber that makes them fairly low GI, but there is a limit to how much fructose you can consume. Fructose is very damaging in the bloodstream so the body turns it into glucose before it gets there, or it sends it to the liver. Fructose does not require insulin to get into the liver like glucose does, but the liver can only manage 25 grams a day, plus about 1/3 of glycogen replenishment from exercise. So you can eat 2.5-5 bananas a day, or about 75-150 grams of carbs from fruit depending on your activity level, but at a certain point the liver will turn fructose into triglycerides, liver fat (both of which make the body secrete more insulin every day) and also spill fructose into the blood which causes glucotoxicity.
So fruit is generally not inflammatory unless you exceed your body’s ability to manage the fructose.
We are left with basically the other two sources of carbs for the balance: the faster glucose polymers/pure glucose like white rice, potatoes and drinks, and the lower GI whole grains and legumes. There simply is not much choice for low GI glucose source that does not contain inflammatory compounds, precisely because the inflammatory compounds are the agent that slows digestion.
Without adding fat, the high GI sources will spike and trough blood sugar. The exceptions would be potatoes allowed to cool down to form resistant starch which is a gut healthy way to lower the GI, as well as possibly banana flour, or you can add an acid like vinegar to white rice-this is probably why rice and potatoes “taste” good with an acid source, because we developed the taste for them that would provide the slow and steady energy release.
As for what are the signs of inflammation from whole grains and legumes, people vary a lot. Some manage them much better than others. One sign is just intestinal discomfort. Another is joint pain, and a third is sinus inflammation and puffiness around the eyes. When I eat wheat, corn or legumes, I get sinus inflammation and can’t sleep. It goes away when I remove them, like clockwork so in my case, they just are not good for me. Rice and potatoes are fine. If you have night time sinus congestion, there is a good chance it is a sign of inflammation from inflammatory carbs, whole grains and or legumes, also possibly dairy and in some cases nuts-particularly the skins.
All of these items end up being inflammatory (as well as being linked to the onset of autoimmune diseases) because they irritate the gut or other tissues causing a release of cortisol, which requires the body to release more insulin to keep blood sugar from rising from the cortisol. Cortisol itself is not inflammatory (it is actually an anti inflammatory, and technically all of the stress hormones are directly anti-inflammatory, but their effect is to raise blood sugar which requires more insulin release. Insulin again IS by definition inflammatory, AND it blocks growth hormone secretion. Growth hormone is fundamental to healing daily tissue micro trauma which triggers more cortisol which triggers more insulin which blocks growth hormone etc. etc.
So in reality; FOOD, that is to say, calories are inflammatory. Ketones even trigger insulin secretion. The key is to eat the calories that don’t provide additional inflammation due to their allergenic, irritant or direct inflammatory effects: basically eliminate high linoleic acid oils that are directly inflammatory, keep sugar/fructose below the harm threshold, and asses yourself for irritant foods like wheat, gluten, corn, oats, legumes, dairy, nuts, egg white.