Three or four weeks have passed since you started working on that ambitious weight-loss resolution. Now the going seems tougher since you have dropped only a few pounds or the bathroom scale is stuck and shows no reward at all.

It’s time to discover the hidden sabotage that could be working against your weight loss. Here are five red flags for the unwary.

You picked a one-size fits all diet

Your low-carb, gluten-free, paleo diet may work in the beginning but ultimately prove too restrictive for you. Even if you lose weight initially, you won’t stick with a plan that tops the best-seller list but leaves you feeling deprived. Tailor your weight loss diet to nutritional foods that you enjoy, and you’ll stick with it longer. Once each week allow yourself a treat meal.

You fix everything all at once

Many people change the way they eat at the same time they start a rigorous workout routine. Your body runs on fuel, and if you’re cutting back on too many nutrients you may deprive yourself of the food you need to power through those workout sessions.

The body adapts to drastically increased exercise and fewer calories by lowering metabolism. You’ll regain the dropped weight if you do too much too soon.

The solution: Start small with changes in both diet and exercise and work up in increments. Let your body adjust to one level before moving on to the next. Cross train and vary your workouts between strength-building, aerobics, and building endurance.

You don’t plan an adequate diet

Let’s face it: you need food to fuel your exercise. Plan to get enough beneficial nutrients that support your exercise program to move longer, stronger and faster. Either meet with a dietician to plan a strategy or do your homework to find the nutrition that will keep you going.

You think energy bars are nutrition

Energy bars are not food. They are a $6.2 billion market of products that are designed to refuel the body after a long workout.  Many are chock full of sugar, calories and fat. Read the labels and find out what you are consuming.

Remember that your body needs the nutrients found in fruits and vegetables. Get protein from poultry, fish and lean red meat; carbs from grains and for protein; and fats from nuts and avocados for fats.

You exercise, therefore you indulge

A pizza after a tough workout does not equal weight loss. Whether you feel the need for a reward after all that hard work or whether exercise makes you hungry, think ahead. Plan to eat a cup of yogurt or fruit before you exercise so you won’t be hungry going in. Take a snack with you so that after you feel the burn, you’re ready with a rice cake or granola bar.

Jennifer Van Allen, co-author of “Run to Lose: A Complete Guide to Weight Loss for Runners,” gives more tips here to avoid weight-loss traps.