Do you know if there’s research linking sodium with a feeling of fullness? I generally keep my sodium around 3000mg a day, but when it drops below that, (say 2300mg) I start to notice that I feel hungrier than usual and have to seek out foods that will keep me feeling full.  I’m not actually sure if sodium is the culprit though (it’s just an observation on my part) so I thought I’d ask!

When it comes appetite or satiety, the first thing that comes to my mind is ghrelin. Ghrelin is a peptide hormone that stimulates appetite. Under “normal” conditions, ghrelin is suppressed postprandially (i.e. after a meal) reducing the desire to eat. However, it turns out that ghrelin is sensitive to “low” dietary sodium intake.

When sodium is restricted, salt-sensitive individuals exhibit increased postprandial ghrelin (relative to normal intake anyway) which may trigger a premature hunger signal leading, in turn, to increased food craving and intake. It is probably for this reason that white individuals in particular tend to lose less weight on combined calorie- and sodium-restricted diets than under calorie restriction alone.

Anecdotally, I have been adhering to an intermittent fasting regimen for the last two years and have found that a 1/4 to a 1/2 teaspoon of sea salt several times during the day really increases my energy and blunts my appetite. Interestingly, research has shown that in the first 24 hours of fasting, sodium excretion accelerates by about 15% above normal which might explain my response.