7 Basic Diet Mistakes Even Smart People Make


When you’re immersed in the world of health and fitness, it’s easy to assume that certain facts are just that—known facts. But actually, there are many basic diet principles that even really, really smart people are clueless about. It has nothing to do with intelligence but rather just not having the right information. Here are seven facts that may seem obvious to the more in-the-know of you out there, but downright earth-shatteringly helpful to the smart guys reading this that just haven’t heard them before.

Fix these basic mistakes with tips from nutritionist and exercise physiologist Marni Sumbal, owner of TriMarni Coaching and Nutrition, and watch your weight loss efforts accelerate and feel way easier in the process.

1. Thinking Fruit Will Help You Lose Weight

Ok, yes. Fruit is healthy. But fruit is also packed with carbs and sugar. So if you’re serious about weight loss you should limit your intake. Basically, eating a bowl full of fruit as breakfast thinking you’re being virtuous is just setting you up for hunger, irritability, and a sugar crash similar to one you’d get from eating a candy bar. But, there’s no need to ditch fruit altogether. “To benefit from the many nutrients found in fruit, combine with protein and fat (like 2% Plain Greek yogurt) for a satisfying breakfast to keep you energized all morning,” suggests Sumbal. 

Read more about whether fruit can make you fat. And check out our ranking of fruit from lowest to highest in sugar.

2. Having an Entire “Cheat Day”

Chicken and waffles for breakfast, a massive meatball sub for lunch, pizza and beer for dinner—and lots and lots of processed snacks in between—is not what experts had in mind when the term “cheat day” was coined. Instead, they meant something along the lines of chicken and waffles for breakfast OR a massive meatball sub for lunch OR pizza and beer for dinner OR a crappy snack in between. “You can still reach your health and body composition goals with the occasional indulgence every now and then, but giving yourself an entire day to eat “off” or “bad” food creates an unhealthy relationship with food and can lead to more restrictive eating habits,” says Sumbal.


3. Being Too Restrictive

That said, there are benefits of having a cheat meal. Check out cheat meal strategies for weight loss and muscle gain. Pick one of those indulgences on the previous slide or something that gets you to salivate even more (check out the 18 best cheat foods of summer for more inspiration)—and enjoy the hell out of it when the time comes. Then, get back on the healthy-eating track.

4. Following Matt’s Diet

Just because your college buddy lost 38 pounds on the Paleo diet doesn’t mean it’s the best choice for you. Turns out, dieting is super personal and the best diet for you is one that is in synch with your lifestyle (do you have to eat out a lot for work—if so, a diet that requires you to cook all your meals isn’t going to work for you), your food preferences (if you love steak and chicken, why go vegan?), and even your DNA (if you’re not allergic to gluten, there’s no need to give it up.)

5. You Eat Too Much “Healthy” Food

Yes, avocados, peanut butter, and hummus are good for you. But “good for you” does not mean calorie-free. Each of these spreads is packed with calories and fat that in moderation are fine and even help keep you feel full, but in excess will pack on the pounds. “Next time you find yourself eating a whole avocado or spreading spoonfuls of nut butter on a rice cake, focus on healthy portions,” says Sumbal. That means 1/2 avocado, 1 tbsp nut butter, or 1 tbsp hummus combined with other foods to create a well-balanced meal. For example, you could try this combo from Sumbal: 1/2 avocado chopped + 2 handfuls mixed greens + 1/2 cup quinoa + 1/2 cup corn. Turns out, even super foods can make you fat…

6. You Eat Back All the Calories You Burned Off at the Gym

It’s easy to get fooled into thinking you “earned” that double bacon cheeseburger during that 30-minute weight lifting session but the sad truth is that working out actually burns off far fewer calories than most of us would like to believe. Actually, if your workout is 60 minutes or less, “a general healthy diet will meet your energy needs,” says Sumbal, meaning you don’t really need any more calories than you’d eat on a normal day. Working out for over an hour? “Add in a little extra energy to your diet like a 200-300 calorie snack like fruit with yogurt or 1/2 nut butter sandwich with carrots,” says Sumbal.


7. You Skip Meals

If it’s a simple equation: Calories in versus calories out, it would make sense that skipping meals would help you to lose weight. But, the equation is far from that simple. Skipping breakfast—or any meal for that matter—simply sets you up to binge eat later in the day and days to come. Focus on getting a good balance of protein, carbs, and fat at least three times a day. “It is well understood that those who skip meals and snacks or go long hours without eating will almost always overeat at some point during the day or week,” confirms Sumbal. “Create a diet that works for you—whether it is three balanced meals and two small snacks throughout the day or five to six mini-meals every few hours,” she suggests. 

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