A former guest Mike Sweeney RD, had an interesting recent interview on a Keto podcast: https://m.youtube.com/watch?v=8fGQ8mU3TGo The claim is at timestamp 46:20. It was interesting to hear a registered dietitian with such *ahem* different views, but I wanted to focus on one particularly interesting claim which I have dug into myself because I previously heard the same claim within the last year. You can listen above for his exact words but the basic claim is this: "Those on low carb diets require less vitamin C than those on high carb diets. This is because Vitamin C and Glucose have a shared transporter (GLUT#). The more carbohydrate in the diet, the more glucose, the more glucose, the higher the vitamin C requirement as they compete for the same transporter. On low-carb, there is less glucose, thus less competition for the transporter, thus a lower Vitamin C requirement." I have heard that this means the RDA for Vitamin C is "irrelevant" and "doesn't apply" to low carb dieters ..... I see a couple of significant problems: (1) Competition for the transporter would only be relevant if either Vitamin C or Glucose were sufficiently high in those areas where the transporters do their job. I believe in the case of hyperglycaemia, there can be an issue with Vitamin C uptake. But where is the evidence that high carbohydrate diets, of themselves result in sufficiently high levels of glucose to make competition for these transporter an issue that would affect Vitamin C requirements? (2) Why would cell requirements for Vitamin C be lower? Rummaging in "Nutrient Metabolism: Structures, Functions and Genes" (Martin Kohlmeier), carbohydrate metabolism does not seem to require Vitamin C. Maybe he is saying that although cell Vitamin C requirements are the same, because of high glucose levels, more vitamin C is needed to outcompete the glucose and reach the cells? It all sounds pretty sketchy so would love to hear you guys take it apart.
Listening to multiple experts, podcast, books etc. I don't know what to eat anymore. There are like pro's and cons for everything. Is there a podcast where the best foods to eat are described. So not just protein/carb/fat, but the actual most benefical foods. etc.
In omega 3 supplementation studies it doesn't seem to be common practice to test the omega 3 index as a baseline measurement before supplementation. Why is this? How do we know if supplementation is beneficial if people do/do not have adequate levels? It seems to be intake is measured off food frequency questionnaires which can have issues, so why don't we use this marker as a standard?