I started writing this as a response to @cooper27's question about dietary advice, but it turned into nearly an essay. So I decided to make it a proper essay.
I have been on quite an adventure finding trusted dietary advice.
I used to listen to the recognised experts until very recently. I was checking the labels to make sure I wasn't eating too much salt or saturated fat and keeping all fat low. I only ate low fat dairy, fat-free or low fat versions of other foods and never bought butter. I was filling 1/3 of my plate with low nutrient grains, because that was healthy. I ate breakfast even if I wasn't hungry and even though I was more likely to need a snack before lunchtime if I ate it than if I didn't, because I was told slim people eat breakfast. I ate frequently to keep my metabolism raised.
I kept doing this even as my weight started to climb up, and dieting only worked in the short term and my once slender waist was replaced with visceral obesity. I kept going even though my BP was gradually climbing, and my hbA1c was moving towards pre-diabetes (though I didn't realise that, and my GP thought it was "good"). I doubled down after an MRI showed me the damage this diet had wreaked on my body, becoming more strict on fats and salt.
I still believed this in October 2019. I decided I was going to really focus on my health and improve it. I installed an app on my phone to count calories. This app immediately put me on a CICO (calories in/calories out) diet - it asked me my age, sex, height and weight when I started using it and immediately suggested a calorie deficit. It linked to a fitness app to log my activity. For three weeks, I let this app rule my life. I weighed every skerrick of food I made (even putting a cold pan on my kitchen scales to record how many grams of oil I was using) and diligently entered all the nutritional data from any package foods I ate if they were not in the database. This took a lot of time, I was obsessed with food and hungry all the time. At the end of 3 weeks, far from losing 1.5kg the app predicted, I was exactly the same weight as when I started. I appealed to the support forums for the app, and was given usual nonsense advice. There was no suggestion that maybe this approach was faulty.
So all the hard work I had done over the 3 weeks turned out to be what I would have to do just to maintain using CICO. Constant monitoring, constant hunger, hours spent obsessively weighing and measuring everything. Never able to relax, never able to eat out, always obsessing about food. It was a red Queen race I was going to inevitably fail at. There was no way I could do this for the rest of my life, and before I could even start maintaining I had 10kg+ to lose by more obsession and more pain than I had already experienced - moving more and eating even less.
So long term weight loss was not an option for me. Unless I did something completely different 💡
After some research, 5:2 diet seemed right. Maintaining would not be a constant obsession, it would just be obsessing 1 or 2 days a week, if the scale crept up. That seemed doable. However, when I tried to get my hands on the diet book, I found a newer version, Fast800. That plan was low carbs and low calorie (800/day) for the first 4-12 weeks, then two 800kcal days per week for the rest of your life.
Low carb with fasting was a revelation! On my previous calorie controlled diet, I was hungry almost constantly, but I would prepare a meal of 500-800 calories but only a few grams of carbs, so I was completely satisfied after eating it and for hours afterwards. If I wasn't satisfied I would eat a little more. The rest of the day I would get hungry for a little while, but I would drink a coffee, and find that the hunger disappeared. If I couldn't fast for the full 20+ hours, I would make myself a smaller meal of 300-400kcals,which would keep me going. I was still well under my daily calorie requirements. So less hungry, less obsessed and the weight was falling off me. I soon didn't even have to log my food, I knew what a meal looked like, and I had 100s kcal margin of error, so I didn't have to obsess.
At the end of the first month, I joined HU for fasting support, found the LCHF group so joined that too. I switched to a more standard keto diet. It took me about 8 months to lose the 20kg that seemed right. That included a few stalls, which I defeated with fasting - some quite intense fasting - but for more than a year I have effortlessly kept my weight were it got to.
My BP has gone back to the level it was in my 20s. My waist, not quite, but well below any red flag levels. I weigh less than I have in my adult life. I haven't repeated any blood tests because of coronavirus, but it looks like my hba1c is below the level it was in 2016, so 🤞 for the others.
I couldn't see any reason to ever eat pure carbs again. My body doesn't need them, they have no nutrients that I can't get elsewhere, and I don't miss them.
So who do I rely on for nutritional advice? I like to go to primary resources, especially studies. My most useful one is the n=1 study I am running on myself. I can't use myself to see what diet is best for preventing heart attack, cancer or stroke - but when I want to know what is best improving the biomarkers of chronic disease, how my own body responds is more useful to me than any study - any study may be flawed, but also there are always outliers who don't respond the way the rest do, so maybe I would be one of them.
Obviously, I need to know about what to try or what to change, then I am very circumspect. The standard dietary advice seems to be based on conjecture, and most of that conjecture has never been proven, despite them trying. Also, the diet pyramid/plate that is recommended across the anglophone world comes not from a medical authority by the USDA - that's Department of Agriculture. Their job is to support farming, not health. Telling everyone in American (and affectively Canada, UK, Australia, NZ) to eat 5-10 servings (🤯) of grain per day is definitely good for agriculture. Is it good for us? I'd say not, from my experience, and from looking around me where 2/3 of adults and many children are overweight - and that humans evolved with very little grain in our diets, so how could it be essential? They also say things like "we don't know the long term effects of low carb", which maybe we don't but we do know the long term effects of low fat - 1/2 American adults have diabetes or pre-diabetes. The resolution to stick to dietary advice that is obviously not working is rather terrifying.
So I listen to people like Eric Westman, Diet Doctor, Low Carb Down Under, David Unwin, Gary Taubes, Nina Teicholz etc. Then I go looking at the papers they are referring to and see if they convince me to make a change.
But also, Dr Google. Eg I suffer cramps, Dr Google says take magnesium. I google downsides of magnesium supplementation. Seems fine. Take magnesium - cramps go away. Simple. No need for anything more complicated.
😂 That was long. Anyone read this far?