Diet long enough, and you're bound to reach a phase where weight loss levels off and the scale is stuck on the same two digits for weeks or more.

In fact, researchers from Drexel University find that dieters tend to reach plateaus at weeks three and 10, and after six months. But plateaus aren't just physical - they can be psychological, too.

Here's a guide to identifying which type of plateau you've hit and how to nudge the scale back to its downward trend.

1,500 calories a day

SYMPTOM: You're eating the same number of calories but you've stopped losing weight.

UNDERLYING CAUSE: As you become leaner, you burn fewer calories during workouts (and when you're resting, too).

THE FIX: Eat five to six small meals every three to four hours, depending on your calorie needs. Don't reduce the number of calories you're eating, but rather, spread calories throughout the day to keep your metabolism running strong.

'If you're losing weight by decreasing calories, you're going to reach a point where you can't cut back more without sabotaging nutrients,' says Dr Jenna Bell-Wilson, a board certified specialist in sports dietetics in Columbus, Ohio in the United States.

That's why it's important to eat low-cal, nutrient-dense fruits and vegetables. What's more, when your body is deprived of energy it can go into starvation mode, slowing your metabolism and making weight loss even more difficult.

Goodie gridlock

SYMPTOM: Constant cravings make it hard for you to pass up on old favourites. Yet, you know those little nibbles of foods you love may explain why you're at a standstill.

UNDERLYING CAUSE: You're bored with your diet.

THE FIX: Shake up your food choices. Load up on different fruits and vegetables, try some new dishes with whole grains or lean protein, and experiment with seasonings.

Look to other cultures for inspiration. For example, try hummus with raw vegetables or Vietnamese spring rolls with rice paper. And when it comes to satisfying your sweet tooth, stick with one or two staples.

Studies show decreasing the variety of high-fat foods you eat can lower your total calories and boost your weight loss.

Having a plethora of high-fat options to choose from encourages you to keep eating so you can experience the different sensory qualities of each food. Remember the old adage, less is more.

Fitness fatigue

SYMPTOM: The workout that used to leave you huffing, puffing, and sore for days barely makes you break a sweat.

UNDERLYING CAUSE: Your body has become more efficient and requires less energy to do the same activity. 'When you get accustomed to your exercise programme, it stops stressing your body,' says Dr Bell-Wilson. And when you stop stressing your body, you stop seeing results.

THE FIX: Add weights, advises Dr Christine Gerbstadt, national spokesman for the American Dietetics Association.
Strength training at least twice a week increases your lean body tissue, metabolic rate and fat burning potential. In fact, a study published in the Journal of the American Dietetic Association found that women who trained with weights twice a week for 12 weeks reduced their body fat by more than 2.5 per cent and increased lean muscle mass by 2kg - even without restricting calories.

Increasing the duration and intensity of your workouts is also a good idea. So instead of logging in your regular 30 minutes on the treadmill at a steady pace, try the treadmill's interval training programme, or hit the road and take advantage of changes in the terrain.

Run in the sand or up hills and use landmarks to signify a sprint or a slow down. And squeeze in extra calorie burning whenever you get the chance, says Dr. Gerbstadt. Getting up to change the television channel instead of relying on the remote control; pacing while you're on the phone; and doing squats while you wait for your food to heat in the microwave.

Mental gymnastics

SYMPTOM: You want to throw in the towel.

UNDERLYING CAUSE: The numbers on the scale stop going down or start to creep up and you feel like you'll never reach your target weight.

THE FIX: 'It's important for people to understand that plateaus are a natural phenomenon and they will occur,' says Dr Gerbstadt.

Instead of despair, arm yourself with a list of strategies to help you break through it. Experts recommend implementing small behavioural changes such as taking a walk around the block after dinner or reducing the amount of dressing on your salad by a teaspoon or two.

And challenge yourself to run farther, lift more weights or experiment with a new activity.

Studies show that dieters who have a positive attitude about their chances for success are more likely to take the weight off and maintain the loss.

OTHER IDEAS: Wear your favourite outfit (one you know you look great in and that will elicit compliments), look at photos of yourself at your target weight (if you were there before), donate clothes that are too big, meditate, call a friend or weight loss counsellor, ask a friend for a compliment, make small positive changes (drink an extra glass of water each day, add more fibre to your diet, try a new vegetable or fruit or substitute a lower calorie version for the full-fat, full-sugar treat).

- FEATUREWELL

This article was first published in Mind Your Body, The Straits Times on Mar 12, 2008.