As you are studying dietetics perhaps you could answer a couple of questions:
1: Is it sensible for an athlete engaged in a strength training program to rely on gluconeogenesis for energy in order to make up for a low energy low carbohydrate diet given the proven and well documented protein sparing effects of carbohydrates?
2: If an athlete came to you complaining of fatigue and of having legs that feel "heavy and slow" and "lack explosiveness" would you -
a/ Address the well known problems associated with athletes consuming diets that are low in both energy and carbohydrates by advising them on how they could improve their performance through dietary changes eg. increasing their calorie and carbohydrate intake then if that failed to improve matters in 4 - 6 weeks order further tests.
b/ Ignore the well known problems associated with athletes consuming diets that are low in both energy and carbohydrates and prescribe vitamin supplements.
1. First of all I think I addressed that quite clearly above, so i won't waste any time commenting on why he (probably) doesn't need to increase his carbohydrate intake. Secondly, Scott has made no indication that he is an "athlete". Saying that Scott is an "athlete engaged in a strength training program" is misleading and not an assumption that you could make based on his post. Suggesting that he is an athlete suggests that he is doing other vigorous sport-specific training on top of his strength program. That may be the case, but he didn't include those details in his post, so there is no way to come to that conclusion. Perhaps Scott could fill us in more on the specifics of his activity level to help clear that up. But until then, all we can assume is that Scott is an everyday guy who does some recreational strength training.
That being said, he should have plenty of glycogen from both dietary sources and gluconeogenesis (I never said he would get ALL of his glycogen from gluconeogenesis, as you've suggested). And that's not even to mention that he clearly stated that he eats cheat meals (which most likely are on the higher carb side) on the weekends.
Carbohydrates are indeed protein sparing, but so is fat, and Scott has an appropriately high fat intake given his lower carb intake.
2. Your critique of my response is completely misguided and out of context, especially considering that Scott has received blood results that indicate that he's low on hemoglobin, which is implicated in anemia. Combine that with the fact that he's presenting symptoms of anemia (you should know that heavy, stiff limbs can be a sign of B12 deficiency) and it becomes obvious that carb intake isn't the main factor here, if at all.
If an athlete came to you complaining of fatigue and of having legs that feel "heavy and slow" and "lack explosiveness" would you -
If the person was an athlete and those were the only symptoms, then yes, I would consider glycogen depletion, but they're not. I already stated the obvious: Scott has blood results to suggest anemia. His symptoms suggest anemia. He probably has anemia.
The reason I suggested a supplement was to help identify the problem. If the supplement corrected the problem then we would know that b-vitamins were the issue and use specific dietary changes to get him back to where he needs to be. If the supplements fail, then we know that it's something else.
Dr. G suggested lead poisoning. I'm not too familiar with lead poisoning and anemia, so I can't comment on that, but I'm sure Dr. G knows more about it than me. I offered my response to Scott in hopes that it may help him if it turns out that lead wasn't the issue. In that case he could look to his digestive system and check for stomach problems or h. pylori.