5 Biggest Mistakes People Make When Trying to Lose Weight

Mistake #1: Cutting Calories Too Aggressively

When people decide to lose weight, the first instinct is to slash calories dramatically. Going from 2,500 to 1,200 calories overnight feels productive, but it backfires. Extreme calorie restriction slows your metabolism through a process called adaptive thermogenesis. Your body essentially goes into conservation mode.

The Fix: Aim for a moderate deficit of 300-500 calories below your TDEE (Total Daily Energy Expenditure). Use our free calorie calculator to find your target. A 500-calorie deficit produces roughly 1 pound of fat loss per week — sustainable and effective.

Mistake #2: Ignoring Protein Intake

Most people in a calorie deficit don't eat enough protein. This leads to muscle loss alongside fat loss, which reduces your metabolic rate and leaves you looking "skinny fat" instead of lean. Research published in the Journal of the International Society of Sports Nutrition shows that higher protein diets preserve lean mass during weight loss.

The Fix: Consume 0.7-1.0 grams of protein per pound of body weight daily. Prioritize lean meats, fish, eggs, Greek yogurt, and legumes. If you struggle to hit your target through food alone, a quality protein powder can help fill the gap.

Mistake #3: Doing Cardio Only (Skipping Weights)

Running on the treadmill for 60 minutes might burn 500 calories, but it does almost nothing for building or preserving muscle. When you combine a calorie deficit with cardio-only training, your body is more likely to burn muscle tissue for energy. Resistance training sends the signal to keep it.

The Fix: Train with weights at least 3 times per week. A basic push/pull/legs split or full-body routine is plenty. Add 2-3 cardio sessions if you enjoy it, but don't rely on cardio alone for fat loss. Check out our beginner strength training guide to get started.

Mistake #4: Not Tracking Anything

"I eat pretty healthy" isn't a strategy. Studies show people underestimate calorie intake by 40-50% on average. Without tracking — even loosely — you have no idea whether you're in a deficit, at maintenance, or in a surplus.

The Fix: Track your food for at least 2-4 weeks using an app like MyFitnessPal or Cronometer. You don't have to track forever — just long enough to build portion awareness. Weigh high-calorie foods like nuts, oils, and cheese at first. You'll be surprised how quickly calories add up.

Mistake #5: Expecting Linear Progress

Weight loss is not a straight line. You'll have weeks where the scale doesn't move — or even goes up — despite doing everything right. Water retention from sodium, stress (cortisol), menstrual cycles, and even sleep quality can mask fat loss on the scale.

The Fix: Track trends, not daily numbers. Weigh yourself at the same time each morning and compare weekly averages. Take progress photos and measurements. If your weekly average is trending down over 3-4 weeks, you're on track — even if individual days fluctuate.