The title is really good advice. To be perfectly fair you shouldn't listen to me either. There is an insane bad signal to noise ratio regarding nutrition, and finding good advice from bad on fitness forums is almost impossible. So don't trust old fat men, and don't trust me either.
So who can you trust? How do you figure out what the right thing to do is?
Trust the pros. A professional cyclist or professional runner might not have a perfect diet. They might drink a beer or two too many. They might eat extra dessert. But when you have a 17 BMI, 8% body fat and a 45 BPM resting heart rate it's highly likely you have some aspects of fitness and nutrition pretty well dialed in. If you read about how evil carbs are from some fat doctor and then you see Kenyan runners with 5% body fat smashing bowl after bowl of white rice who do you suppose is more likely to be right? I will side with the diet of the fit person when receiving conflicting reports.
Don't trust doctors who recommend meat, dairy or eggs. These studies (and consequently these doctors) are bought and paid for by the animal agriculture industry. You will never find a study without ties to Big Ag that finds it beneficial to eat dairy or eggs. You will never find a study without ties to the meat industry that says a diet with meat in it is superior to a diet without meat. These people are not looking out for you, they are shills. Do trust doctors who recommend fruits and vegetables; they aren't shills and they aren't being paid by the USDA. There is no banana lobby working inside the FDA.
Don't trust bros at the gym or crossfit camp. Why is their advice faulty? They might have big muscles and they might be strong, and some of them might even be fit too, but at the end of the day they at at the gym for aesthetic purposes not fitness. Any of these swoll bros would happily trade higher cholesterol, higher resting heart rate, slower 1 mile run time in order to make aesthetic gains. At the end of the day, almost all of them care about looks > health. This goes back to the trust the pros. A professional NFL strong safety has the same aesthetic build that a pro wrestler has. Difference is, the Safety is paid to be strong, fast, and agile. The wrestler is paid to look good oiled up. Health is high up on the NFL player's priorities. Aesthetics is not.
If you follow these steps you will start to develop a paradigm you can trust.
So what made me so angry? This forum post: https://t.co/fg4vJFYnn3 Literally everything he said is at least partially wrong. I know this is an ad hominem attack but... he is an old, fat diabetic. Why the fuck would anyone listen to him? If he had any special insight into nutrition or fitness he wouldn't be fat and diabetic. I know plenty of 60+ year old men who are fit as fuck, so age is not the issue.
Let's dissect this point by point.
"I have been on a ketogenic diet because I'm a type 2 diabetic."
"I lost 50 lbs and dropped my a1c from 8.9 to 4.7. There are quite a few misgivings in this thread."
You lost weight because after your diagnosis, for the first time in your life, you started paying attention to your intake and started cycling. Kudos on that, but your ketogenic diet had little to do with it. You started eating less and exercising more and it lowered your blood sugar. That's good, but again, any Type 2 diabetic who started eating less and exercising more would get the same results. Also, you're not cured. You simply have your disease 'under control" by means of strict carbohydrate restriction. There are a lot of "misgivings in this thread" but they are being promoted by fat old men who don't know shit about nutrition, like yourself.
"1. Calories in, calories out is a myth. What causes people to gain weight is too many carbs."
The first part is partially wrong the second completely wrong. Calories in calories out is 100% factual, barring the effects of metabolic damage or thyroid conditions. How much you eat determines your weight, period. What you eat affects your body composition. If you eat 1200 calories per day of Twinkies, you will lose weight, proven fact. If you eat 1200 calories per day of Twinkies you will not have a lean, muscular body composition. You will be skinny fat. You will weigh very little, but what little there is will be bone, water and fat.
Carbs cause you to get fat? I am 6'3, weigh 160 lbs and have 10% body fat. I eat about 3,000 calories per day and 75% of my calories are from carbohydrates. How is that possible then? According to you, I should be a type 2 diabetic and obese. Yet I am lean as fuck and fit as fuck, and you are fat and sick. Maybe you don't care about me. Let's look at some other folks who have similar diets to my own, or even eat MORE carbs than I do...
Oh look! It's Chris Froome, the fastest cyclist on the planet! He is lean as fuck, and one of the fittest humans alive. And he eat 5,000 calories per day and most come from carbohydrates!
Hey its 3 rail thin lean Kenyan runners! They eat 90% of their calories from carbohydrates, mostly corn and rice. WONT SOMEONE WARN THEM OF DIABETES?!?!
This Mr. Bolt. He is the fastest human being alive. Does he practice a ketogenic diet?! No. He derives most of his caloric intake from carbohydrates. Shocking!
See a trend here Mr. Fat Diabetic Englishman? The fittest people you will ever encounter eat a particular diet: high carbs, low fat. They don't have diabetes. They are not fat. I think I've made my point here.
"Even if your not a diabetic, a ketogenic diet is healthy for you because it reduces inflammation which makes you healthier and butter makes your pants fall off."
Tell me another knee slapper! First, ketogenic diet is not healthy. Ketogenesis is a metabolic response, where your body starts burning fat and muscle instead of sugar for energy. It is a biological response to starvation. Essentially, by eating no (or very low) carbs you exhaust your body's glycogen (sugar) supplies and you go into Starvation Mode and your body begins to eat itself for fuel. This... is not sustainable and not healthy. This is what people on desert islands do in order to avoid dying. This is what our ancestors did on the African Savannah 100,000 years ago when they weren't able to gather enough fruit to survive during a drought. It is no something you should live with for the rest of your life. It works for grossly overweight people because they do have a lot of fat stored that they can burn for fuel. But it's a crash diet, you can't possible sustain that, and no lean person should even consider it.
Secondly, not a single professional athlete in any sportpractices a ketogenic diet during competition. All sport comes down to having more endurance or more strength than your opponent. People who have no glycogen in their bodies are have no endurance, and no strength. It's impossible to compete when your body is in a starvation mode against people who are well fed.
In running and cycling there is a word for competing when your body exhausts its carbohydrates and goes ketogenic: bonking. A bonk happens mostly when you forget to eat or due to the intensity of the race, cannot take time to eat. Your body exhausts its sugar fuel and switches to ketogensis. It goes into LOW POWER MODE. When you are bonking summoning even 1/4th of your strength is a titanic effort. There are countless videos of the top runners and cyclists bonking and being left behind by their competitors like they were standing still.
Why would you recommend, on a cycling forum, a diet that is 100% incompatible with endurance sport?
"3. Ketogenic diet means you are a fat burner, not a carb burner. Fat burns slower and keeps you full."
Fucking nonsense. You're right as I described above you burn fat instead of sugar in an incredibly inefficient process that leaves you weak and devoid of energy and strength. "Fat burns slower." Thanks for proving my point.
Fat does not "keep you full." I hear this line time and again. Carbs are empty and leave you hungry. This is all based off a discredited study that created the bullshit "satiety index" which states that protein and fat is more "filling." It's junk science but its been repeated enough to be considered true by the ignorant. No, 2000 calories of beef is not more "satisfying" than 2000 calories of bananas. If you eat 20 bananas you will be just as full if not fuller than 2000 calories of beef. Satiety index is horseshit.
"4. Even if you don't go to a full ketosis diet, you can do yourself a world of favor staying away from processed foods."
This is a pretty big non-sequitor. You can eat a ketogenic diet full of processed foods. You can eat a ketogenic diet made up of lightly processed grassfed beef. You can eat a vegan junk food diet or you can eat a whole food vegan diet of 95% fruits and vegetables. Processing has nothing to do with ketogenic or non-ketogenic. I will agree that the fewer processed foods the better, but that has nothing to do with ketogensis.
He is advising people to "do themselves a favor" and go ketogenic, but he should do himself a favor and read Dr. Bernard's book and cure his diabetes. He should stop giving diet advice on an endurance sports forum that will catastrophically impact the subject's ability to perform endurance sports. He should get his cholesterol and blood pressure checked because while he might have his sugar under control, a diet high in animal fat and protein will simply be changing the cause of his death from diabetes related to heart failure.