“How did the Israelites sustain themselves for 40 years?” Ensign, Oct. 1973, 58
When the Israelites were in the barren wastelands the Lord provided manna from heaven for their basic diet. Flaky, small, and white, it resembled the fruit of the coriander and tasted like honey wafers or oil. It could be ground, stewed, or baked and was gathered fresh early each morning because it would melt if exposed to the sun and would spoil if kept overnight. On the day before the Sabbath, a special double portion was provided so that no one would have to labor on that special day.
Apparently manna provided enough nutrients to sustain life; but for variety, quail were supplied on a couple of occasions. Of course the Israelites had their flocks with them, and the animals supplied the necessary meat, milk, and cheese.
In the Kadesh-Barnea area, where they stayed for many years, the Israelites had water for irrigating grain crops. Even today this area, known as Wadi Feiron, has some water and miles of date palms.
Thus, the Israelites could have supplied many of their nutritional needs independent of manna.