|You don't need supplemental K, well... unless you are on a protein modified fast without fruits and veggies ;-)|
Or, put simly, the scientists wanted to know if a low potassium level may promote insulin resistance and modify or is modified in response to dieting (in this case protein-modified fasting). In the study, two groups of subjects were studied. The "normal" group consisted of ten subjects, who were 27-45 years old and whose body weights ranged from 89 to 115% of the "ideal body weight". The "obese" group group consisted of twenty subjects aged 21-48 years who were 70%-131% overweight.
Before the obese subjects were put on a protein modified fast (PMF) all subjects, lean or obese, received a "weight-maintaining diet" with 200g/day carbohydrates for 8 days.
"The diets were calculated according to individual tastes, employing varying proportions of egg white, beef tenderloin, skim-milk cheese and water-packed canned tuna. For the PMF, total calories varied from a mean of 350-399 in individual subjects, with a mean of 378+/-36 (SD)
Figure 1: Macronutrient composition of the ~380kcal PMF diet (Norbiato. 1984).
[...] Calculated protein intakes, according to standard tables, were 70.8+/-7.6 g/day (about 79% of calories). Calculated fat intake was 5.7+/-3.5 g /day (19% of calories). Carbohydrate contributed 3.2+/-1.3 g/day, 2% of caloric input" (Norbiato. 1984).As far as its potassium content is concerned the PMF diet was (as probably most diets that are almost exclusively protein) on the skinny side (15 +/- 3.9 mmol of potassium/day | adult men and women should get 100mmol/day and 72mmol/day, that's 3,800mg and 2,800mg/day or 8-9 bananas if you want to "go bananas" instead of leafy greens ;-). Nevertheless, only 10 out of 20 of the obese subjects received an oral potassium chloride (64 mmol/day) supplement (KC1-retard, Zyma, Italy). The other ten patients received identical placebo tablets.
|Relation between percent change in total body potassium (%ATBK) as a result of potassium depletion protocol and the corresponding percent change in serum insulin response (%A I)to steady state hyperglycemia (Rowe. 1998).|
As the figure on the left hand side of this box shows, the association between potassium depletion and the reduction in insulin secretion is almost linear (Rowe. 1989) - in other words: The lower your potassium, the less insulin you produce and (in conjunction with the reduced peripheral glucose uptake) the higher your glucose levels will rise.
- Norbiato, Guido, et al. "Effects of potassium supplementation on insulin binding and insulin action in human obesity: protein‐modified fast and refeeding." European journal of clinical investigation 14.6 (1984): 414-419.
- Rowe, John W., et al. "Effect of experimental potassium deficiency on glucose and insulin metabolism." Metabolism 29.6 (1980): 498-502.