Attempting to gain 10 pounds of "healthy" weight in a single week is medically inadvisable and physically impossible for most adults, as it would require a caloric surplus of 35,000 calories. Any "gain" of that magnitude in such a short time would almost certainly be water retention or significant bloating rather than muscle or healthy fat. For those looking to gain weight in 2026, a "healthy" rate is 1 to 2 pounds per week through a caloric surplus of 500 to 1,000 calories per day. This is best achieved by focusing on "nutrient-dense" foods such as avocados, nuts, seeds, nut butters, whole grains, and healthy oils like olive oil. Drinking "liquid calories" such as protein shakes or smoothies is also a highly effective "pro" tip for those who find large meals overwhelming. Additionally, resistance training (lifting weights) is essential to ensure that the weight you gain is muscle mass rather than just body fat. In 2026, "mass gainer" supplements are popular, but they should be used as a supplement to—not a replacement for—a balanced, whole-food diet to ensure long-term health and metabolic stability.