And now, the wildcard for sculpting a better midsection, for putting the finishing touches on your ab training and diet: fat-burning supplements. The six-week Spot-On Abs training and diet program is designed to maximize fat loss from your midsection as well as the rest of your body. Taking the right supplement stack as you follow this program will further enhance those ab-revealing effects. These five products, taken together, will ensure that your six-pack is as tight as possible in six weeks.

Conjugated Linoleic Acid (CLA)

This healthy fat can help you drop abdominal and all-over bodyfat, while helping to add muscle mass and boost strength. One benefit of CLA is that it inhibits the fat-storing enzyme lipoprotein lipase, which prevents the storage of fat and encourages the burning of fat as fuel.

A study presented at the 2006 Experimental Biology Conference (San Francisco) reported that subjects taking 3.4 grams of CLA per day without diet or exercise for six months lost roughly 5 pounds more bodyfat than subjects who consumed olive oil, and this fat loss came primarily from the abdominal region. In addition to loss of bodyfat, the increase in fat-burning from CLA spares muscle mass. The aforementioned study also found that subjects taking CLA gained about 1 pound of muscle mass without any exercise.

Furthermore, a University of Saskatchewan (Saskatoon, Canada) study discovered that subjects taking 5 grams of CLA while following a seven-week weight-training program without dieting gained significantly more muscle mass and strength, while simultaneously losing more bodyfat than subjects taking a placebo.

>> SPOT CHECK Take 2 grams of CLA with breakfast, lunch and dinner while following the Spot-On Abs training and diet program, and consider taking it after the program, as CLA's benefits increase with time of use.

Carnitine

During the low-carb days of the Spot-On Abs diet, your body will be forced to burn more fat for fuel. To do that successfully, the most critical step is getting the fat into the machinery of the cells, particularly muscle cells, where fat is converted (burned) into usable energy. This microscopic machinery is known as the mitochondria. Fat must be carried into the mitochondria by carnitine, an amino acid-like molecule. When there's a lot of fat to be burned, such as during a low-carb diet, more carnitine is needed, so supplementing it ensures that the fat gets into the mitochondria and is burned for fuel, further encouraging fat-burning.

Research confirms this. One study from a 2004 issue of the journal Metabolism found that subjects taking 3 grams of carnitine per day for 10 days significantly increased the amount of fat they burned. Taking one dose of carnitine before exercise is particularly beneficial, as research shows carnitine levels in muscle decline during exercise, which may compromise fat-burning. Yet when subjects are given carnitine before exercise, they burn more fat for fuel and take much longer to fatigue. One study performed at the Institute of Clinical Physiology (Pisa, Italy) found that subjects taking 3 grams of L-carnitine before exercise on a stationary cycle increased fat use during exercise by almost 25%. Therefore, taking carnitine will help you burn more abdominal fat during your ab workouts and also tolerate them better.

>> SPOT CHECK Take 3 grams of carnitine in the form of L-carnitine or acetyl-L-carnitine with breakfast as well as immediately before and after workouts.

5-HTP

For guys who are used to eating carbs with most meals, switching over to a low-carb plan can be challenging due to carb cravings caused by low levels of the hormone serotonin. Serotonin levels tend to drop when dieting, especially with lower carb intake, but staggering lower- and higher-carb days in the Spot-On Abs diet should help prevent the typical drop in serotonin, as well as most carb cravings.

However, regardless of the cycling, many guys will still crave carbs, particularly later in the evening when carb intake needs to be limited the most. To stop these cravings, try the modified amino acid 5-Hydroxytryptophan (5-HTP). The essential amino acid tryptophan gets converted into 5-HTP before it forms serotonin and melatonin in the body, which will help curb your carb cravings and relax you before bed. One study from the University of Rome found that obese subjects taking 5-HTP consumed fewer calories per day and lost an average of 11 pounds in 12 weeks, while those taking a placebo had difficulty limiting their food intake and lost an average of only 2 pounds.

>> SPOT CHECK Go with 50-300 mg of 5-HTP in the evening, as needed.

Green-Tea Extract

To maximize fat loss, you need to maximize the effects of your body's hormones. One hormone critical for fat loss is norepinephrine (NE), which raises metabolic rate and enhances the release of fat from fat cells. So when you're trying to drop bodyfat, you should make sure to keep your NE levels up. Green-tea extract is the perfect supplement with which to do so because it contains epigallocatechin gallate (EGCG), the active compound that inhibits the enzyme that normally breaks down NE and helps keep the metabolism revved up.

One study from the University of Geneva (France) found that men given green-tea extract three times a day with meals increased NE levels, metabolic rate and fat oxidation. Another study in a 2005 issue of Medicine & Science in Sports & Exercise reported that mice that exercised and were given green-tea extract lost 87% more visceral fat than control mice.

>> SPOT CHECK Take 500 mg of green-tea extract standardized for EGCG three times a day between meals. The supplemental form is the preferred way to get EGCG, as one study from the University of California, Los Angeles, found that EGCG was absorbed better from green-tea extract supplements than from green tea beverages.

Creatine

When your carbs are low on workout days, as they will be on Mondays, Wednesdays and Fridays, your body will rely less on carbs for fuel and more on fat and the quick form of energy, creatine phosphate, stored in muscle cells. Creatine phosphate rapidly forms adenosine triphosphate, the energy source your muscles need to contract when training with weights. Taking a creatine supplement is important when following diets low in carbs because it ensures that your muscle levels of creatine are maximized. This will help you crank out more reps without fatiguing too quickly, which is critical on ab workout days.

As an added bonus, supplementing with creatine can also enhance fat loss. A 2001 study in the journal Metabolism reported that creatine supplementation increased not only strength and muscle mass but also resting metabolic rate by more than 100 calories per day. Another study found that soldiers taking creatine for just one week experienced increased strength, muscle mass and decreased bodyfat compared to those taking a placebo.

>> SPOT CHECK Take 5 grams of creatine immediately before and after workouts. On Sundays, take it with your midday snack. M&F

FAT-ATTACK STACK

Follow this supplement regimen to melt more ab fat over the course of the six-week Spot-On Abs program.

Supplement Dose/Timing
CLA 2 g with breakfast, lunch and dinner
Carnitine 3 g with breakfast and immediately before and after workouts
5-HTP 50-300 mg in evening, as needed
Green-Tea Extract 500 mg three times per day between meals
Creatine 5 g immediately before and after workouts

100 >> Number of extra calories burned per day when supplementing with creatine