Chia seeds Small but mighty, these guys are a great source of energy. Chia seeds soak up fluids and can expand to as much as 10 times their size in the stomach after being digested. This helps you feel full for longer periods of time. They’re packed with antioxidants, vitamins, and minerals, protein, fat, and fiber. Experiment with chia pudding or sprinkle chia seeds onto your next smoothie.