Sometimes you get a little more than you bargained for with your kung-pao chicken or your sugar-free pudding.

Namely: additives.

For some people, these instigate headaches, allergy-like reactions or even heart palpitations. See if these ingredients are the culprits:

Sulfites: Sulfur-based additives used mainly to prevent darkening of light-coloured vegetables and fruits, and to stop the growth of microorganisms in fermented products, such as wine. Some people have allergy-like reactions to them that can be life-threatening. Fortunately, the label is required to tell you that sulfites are present.
Aspartame: This no-calorie sweetener is associated with headaches in some people. Whether it limits the brain’s ability to use certain vitamins, flavonoids and the mineral magnesium is yet to be nailed down.

MSG (monosodium glutamate): Used for years in restaurants, it overstimulates certain taste receptors so you sense salt and sweets more. But in some people, it is associated with problems including headaches, sweating, flushing, tingling around the lips and mouth, heart palpitations and even shortness of breath and nausea.

Check labels to eliminate these food additives or, even better, eat whole foods that don’t contain additives at all.

A GOOD PORTION: When is the last time you were served a CD-sized pancake? How about a scoop of low-fat frozen yogurt that’s half the size of a tennis ball? Technically, those small portions are what a “serving size” is supposed to look like.

Want to get back on proper portion track? Remember these rules:

1) One bag, one carton or one tub does not equal one serving. An average bag of tortilla chips contains 13 servings, and about 1,820 calories. Repackage large bags into single-serve (ideally 100-calorie) bags.

2) Assume that everything you are served is much more than a “serving.” Proper portions look like: a deck of cards or a BlackBerry for three ounces of meat or poultry; your fist for a baked potato; a small can of tuna for one bagel portion; half a tennis ball for a serving of veggies.

3) Savour it! Go for quality, not quantity.
4) Have some tomorrow. A doggie bag is a beautiful thing. Just ask your belt.
EAT THIS TO BURN FAT: In a recent study, women saw that the same 60-minute walk could torch more or less fat, depending on what they ate first. The secret is “low glycemic index” foods. High-glycemic-index foods – including white bread and Cap’n Crunch – raise your blood-sugar levels fast. Low-GI foods keep things more even, and include most whole-grain foods and no-sugar yogurts.

On days when the women ate a low-GI breakfast – muesli, skim milk, apple juice, an apple, canned peaches and yogurt – they burned a higher percentage of fat than on days when they ate cornflakes, white bread, jam, skim milk, margarine and a sugary drink. (Those days, they burned more carbs.)

SIMPLE SWAPS: When it comes to fibre, chances are you’re getting less than half of what you need (most people do). That means you’re missing out on lowering your weight and blood pressure as well as your risk of heart disease and diabetes.

It’s not hard to get the 25 to 35 grams of fibre a day that make your body younger. The secret: Think texture. The bonus: Texture ranks right up there with flavour.

Get more at every meal with these simple changes:

Breakfast: Start with half a bowl of your favourite cereal and blend high-fibre cereal into it. Gradually increase the amount of high-fibre stuff until you’re eating it almost exclusively at three to five grams of fibre.

Lunch: Try adding garbanzo beans to chicken tortilla soup, peas to chicken noodle soup and kidney beans to chili. Sprinkle beans liberally on your salads. A half-cup of beans delivers five to eight grams of fibre.

Dinner: Whole-grain pasta has up to three times the fibre of regular pasta. Enrich marinara sauce with a cup of high-fibre cooked vegetables such as broccoli or artichoke hearts.

All these fixes will also give you better sex and healthier skin, too. How’s that for inspiration?