USDA ignoring the science on low-carb diets

Because the metabolism of the proteins requires not only oxidation reactions, which are shared with the oxidation of carbohydrates and fatty acids, but also many other chemical reactions, mainly involved in the transfer of the amino- group between various molecules, until eventually it accumulates in urea, which can be excreted.

The total capacity per day of performing those reactions is not sufficient to allow the production of enough energy from proteins to sustain a human, unlike in the carnivore animals.

When too much proteins are eaten, some intermediate molecules accumulate in excess, instead of being converted into excretion products.

Before the 20th century, when this was not understood yet, there have been many cases of illness or even death among people who ate too much lean meat, mainly among European hunters or explorers of the Northern regions, until they learned to copy the methods of the natives, e.g. by eating pemmican, in which the lean meat is mixed with enough fat to provide sufficient energy without having to eat too much proteins.

Like for any food component, for proteins it is bad both to eat too little and to eat too much, but there is a large enough interval of protein quantities per day that are all right.

If you want to try low-carb, note that the health effects of lower carbs usually aren't going to be binary. That is you aren't going to have no improvement until carbs go below some threshold and then you suddenly have the full possible improvement as soon as carbs cross that threshold.

In particular you don't have to go to one of the very very low carb diets like keto to get significant benefits. Much of the published research that finds benefits in low carb diets used diets of up to 30% of calories from carbs.

Personally I'd suggest starting off with a target of 40% or fewer calories from carbs. I suggest 40% for three reasons.

1. It's well below both the level of the USDA recommended diets and the even higher amount of carbs that most typical Americans eat. Even if you might achieve more benefit at some even lower level, many people will be able to achieve their goals at 40%, which is an easier target.

2. The math of 40% carbs fits in well with the information on nutrition labels, because 1g of carbs is on average about 4 calories. This means that if the label says some item has C calories, then the number of grams of carbs it can have without going over 40% is C cal x 40% x 1g/4cal = C/10 grams.

For example part of my breakfast today was a sausage, egg, and cheese croissant sandwich. 390 calories, 29 grams of carbs. 390/10 = 39, so this thing was under 40% calories from carbs.

3. 40% is not hard to achieve without giving up much of what you probably currently eat including fast food, pasta, bread, and sweet deserts. I think a lot of people fail at the very low carb diets because they can require major changes to what you eat and often require that you either do a lot more home cooking or eat at more expensive restaurants.

If you decide to try this here are some tips for executing. (Actually they should work for other percentages besides 40%).

1. Most meals consist of more than one thing, so you probably should be looking at the meal as a whole rather than the individual items. If one some items go over 40% and some are under, but total carbs for the mean is not over 40% of total calories it should be OK.

I'm not sure if that reasoning carries over to longer timeframes like days or weeks. When you eat a meal it is all going to get processed at about the same time. So a meal that consists of say one high carb item and one low carb item should be about equivalent to a meal that consists of a single item with the combined calories and carbs.

If you eat a high carb breakfast, say, and try to balance it with a low carb meal so the daily numbers look good, I'm not sure that would work because the breakfast was already processes before you had dinner. Whatever harmful effects high carbs have might have already taken place. Same of weekly or longer numbers.

Thus my current feeling is to aim for 40% max for every meal.

Anyway, there are a couple of ways to do the math for a meal. Let's say I'm thinking of ordering a cheeseburger (300 cal, 30 g carb) and medium fries (320 cal, 39 g carb) from McDonald's for lunch.

One way would be to add things up, giving 620 cal and 69 g carb. I can see that 620/10 = 62 g of carbs allowed, which is under the 69 g of carbs in the meal, so not good.

A simple way I think is to do each item separately, keeping track of a running net carb allowance. So cheeseburger is 300/10 = 30 g allowed carbs and has 30 g carbs, so we are net 0 g carbs. The the fries are 32 allowed 39 g actual, so 7 g over. That brings is to a net 7 g over.

2. If the numbers aren't quite working out for a particular meal, you might be able to fix them by modifying the items. Maybe switch condiments (go from light mayo to regular mayo) or add more meat.

For example, if I change my proposed McD's lunch to have a double cheeseburger (450 cal, 32 g carb) instead of a single cheeseburger, now the double cheeseburger starts us at 13 g carb below target. The fries add 7 g excess carbs, leaving us 6 g of carbs under target.

This is the key to doing 40% without having to totally change how you eat. But be careful with this because those mods usually involve adding calories. Don't let that get out of hand.

One way to address that is portions. For example lets say you were going to eat a whole medium pepperoni and sausage pizza but see that it is over on the carbs but doubling the pepperoni will bring it under. But then it is more calories than you want.

You might drop the size down to a small, and then bring the calories up to what you want by also doubling the cheese and the sausage.

You might not have to worry as much about extra calories as you might think. What I found is that adding low-carb or carb-free calories (extra meat, mayo, butter for example) to get the percent of carbs down to 40% also made the food more satisfying. I actually started the 40% carbs diet just to see what it would do to blood sugar, expecting to maybe gain some weight during the experiment, but found that I actually started losing weight because my total calories had gone down due to the food being more satisfying.

But be careful if you try this. I may be a fluke and purposefully adding fat/protein calories to your food might just make you gain weight.

Simply put, any form of restriction diet tends to cause people to eat less. That can be restricted time or restricted options. People who eat less tend to lose weight, and some of that weight comes from fat.

People who lower their bodyfat have so many kinds of improved blood markers.

To make a point this guy lost 27lbs on twinkies : https://www.cnn.com/2010/HEALTH/11/08/twinkie.diet.professor...

The only free lunch (pun intended) I think I've observed seems to be protein and unprocessed foods are harder to digest and thus cost some digestion calories (increase the out side of the equation).

When someone tells you that "people lost weight on Diet X" you need to think "Did they lose more or less than on a standard diet equated for how processed it is (fiber), calories, and protein?".

Source: This is all summarized well in the book Fat Loss Forever by Layne Norton and others

Marathon running is typically at a steady pace with only minor variations in the energy output needed. Except for time trials, cycling power is a lot more variable. A cyclist in a road race might be cruising along in the peloton for most of the race but then have to sprint near maximum power to attack or chase several times at unpredictable intervals. So training plans focused on one sport or the other end up looking significantly different in terms of target heart rate zones or perceived exertion, even when training for races of similar duration.

Some people make coffee with eggshells to help reduce the acidity. I started an experiment recently with my girlfriend to keep eggshells to see if it helps her. I hadn't looked for low acid coffee, thanks. That's probably also worth trying.