5 Breakfast Mistakes That Quietly Cause Weight Gain After 40
Are your breakfast habits preventing you from losing weight? We asked nutritionist Sarah Garone, NDTR, CNC, the mistakes people might be making after 40 which are quietly and steadily causing weight gain. “As we age, our metabolism tends to slow down—so don’t be surprised if, after 40, you’re not able to eat a high-calorie breakfast without it contributing to your weight,” Garone says. Here are five breakfast mistakes that could be undermining your health and fitness regimen.
Not Watching Portions
Garone warns against not watching portion sizes as your dietary needs change with age. “Just like at any other meal, portion control is key at breakfast,” she says. “Use printed serving sizes as a guide for your portions. Rather than eyeballing it, consider measuring out specific amounts of breakfast foods with measuring cups or other tools.”
Overdoing It on Added Sugars
Garone says breakfast is probably the most sugar-saturated meal Americans eat, with sugary pastries, breakfast cereals, and other sweets all common as a breakfast choice. “But simple sugars like the ones in these foods aren’t very satiating,” she says. “They get digested quickly, giving you a rapid boost of energy—but after that, you might find yourself hungry mid-morning. For a breakfast that’ll keep you satisfied until lunch, swap a high-sugar option for something high in fiber and protein.”
Skimping on Protein
While the current protein craze may be a bit overhyped, Garone says, that doesn’t negate the satiating effects of this macronutrient. “While not everyone needs copious amounts of protein first thing in the morning, a higher-protein breakfast is more likely to keep morning cravings at bay,” Garone explains. “At the first meal of the day, try including a source of lean protein, such as nut butter, eggs, beans, or poultry sausage.”
Not Eating Enough Fiber
Garone says fiber is a prime nutrient for keeping you full (and, ultimately, for keeping excess weight from creeping up). “Getting more fiber at breakfast may have ripple effects throughout the day,” she says. “Some research even shows that people who eat a breakfast high in fiber are more likely to eat a nutrient-dense dinner! Choices like refined grain cereals or pastries won’t do the trick for fiber, though. Instead, opt for fiber-rich choices like oatmeal, a veggie omelet, or a breakfast burrito with beans.”
Skipping Breakfast
Garone explains that while weight loss is ultimately a balance of calories in and calories out, skipping breakfast is not necessarily a good idea for moving the number on the scale. “According to 2025 research, not eating breakfast disrupts metabolism, impairs the gut microbiome, and raises the risk of obesity,” she says. “So go ahead and eat in the morning! Just be sure your first meal is appropriately portioned, and try to include a source of fiber, protein, and fat.”