If you choose carefully, beef jerky. Made from dried, lean meat, it’s high in protein, and typically low in carbs and sugar. It’s also easy to find in most convenience stores, and stays fresh stashed in a bag or drawer for years on end. The downside is that it can be high in sodium, and some varieties are made with harsh nitrites. Pay attention to the nutrition label to find ones that promise no preservatives, and avoid flavoured varieties that tend to go heavy on the salt content.