How Much Salt You Actually Need on Keto

The ketogenic diet alters how your body retains water and electrolytes. Within days of reducing carbohydrates, glycogen stores deplete, taking with them significant water weight—and the sodium dissolved in that water. This physiological shift explains why many experience fatigue or headaches during the keto adaptation timeline.

Why Sodium Matters More on Keto

Insulin plays a key role in sodium retention. Lower insulin levels on a ketogenic diet cause the kidneys to excrete more sodium. A 2013 study in the European Journal of Clinical Nutrition found that sodium excretion increases by approximately 300-500 mg per day during carbohydrate restriction (Sumithran et al., 2013). This explains the dizziness some report when standing quickly—a classic sign of low blood volume from sodium loss.

What This Means in Practice

UK dietary guidelines recommend no more than 6 g of salt (2.4 g sodium) daily for adults. However, keto-specific research suggests 3-5 g of sodium (7.5-12.5 g salt) may be necessary to compensate for losses. At Tesco, a 350 g tub of LoSalt (a potassium-sodium blend) costs £1.85 and provides an affordable way to meet these needs. In winter, when sweat losses decrease, aim for the lower end of this range.

Recognising Low Sodium Symptoms

Early signs include:

Persistent thirst unquenched by water
Muscle twitches, especially in calves
Brain fog or difficulty concentrating

These often resolve within an hour of consuming 1-2 g sodium dissolved in water. Bone broth, olives, and cured meats also help. common keto electrolyte mistakes include over-relying on magnesium while neglecting sodium.

Sodium Sources Beyond the Shaker

| Food | Sodium per 100 g | |—————–|——————| | Anchovies | 2.8 g | | Feta cheese | 1.1 g | | Sauerkraut | 0.7 g | | Sainsbury’s smoked salmon | 1.5 g |

Frequently Asked Questions

Can I use regular table salt?

Yes, but iodised salt supports thyroid function. Pink Himalayan or sea salt provide trace minerals but aren’t superior for sodium replenishment.

Does this increase blood pressure risks?

For most, no. A 2017 Nutrients review found low-carb diets typically improve blood pressure markers despite higher sodium intake (Kosinski & Jornayvaz, 2017). Those with hypertension should monitor under medical supervision.

What if I exercise intensely?

Add 1 g sodium per hour of sweat-inducing activity. A pinch of salt in your water bottle helps prevent cramping.

The Bottom Line

The ketogenic diet increases sodium requirements due to altered kidney function and lower insulin levels. Aim for 3-5 g sodium daily from foods and supplements, adjusting for activity and season. Symptoms like fatigue often reflect sodium deficiency rather than carb withdrawal. If you’d rather not do the macro maths yourself, the Keto Dieting app does it for you on Google Play and the App Store.

Educational only — not medical advice. This article is for general information. Speak to your GP before changing your diet, especially if you have type 1 or type 2 diabetes, kidney or liver disease, are pregnant or breastfeeding, or take medication for blood pressure, cholesterol, or blood glucose.

References

Sumithran P, Prendergast LA, Delbridge E, et al. (2013). Ketosis and appetite-mediating nutrients and hormones after weight loss. European Journal of Clinical Nutrition. https://doi.org/10.1038/ejcn.2013.90
Kosinski C, Jornayvaz FR (2017). Effects of Ketogenic Diets on Cardiovascular Risk Factors: Evidence from Animal and Human Studies. Nutrients. https://doi.org/10.3390/nu9050517