Overweight and Obesity

How does weight gain occur?

Weight gain occurs when more calories are eaten from all foods than are used for normal bodily functions (e.g., heart beating, breathing) and physical activity. All food sources of protein, carbohydrate (sugars, starches, fibre), fat, and alcohol contribute calories. All of these nutrients can be converted into body fat if eaten in greater amounts than needed by the body. Many factors contribute to people eating more calories than they use, including social and cultural factors, and genetics. There is no single factor that causes weight gain.

Energy In
Carbohydrate  0.55
Fat 0.3
Protein 0.15
Energy Out
Basal Metabolic Rate 0.6
Physical Activity 0.3
Feeding 0.10

Is sugar fattening?

Sugar, like other carbohydrates, contributes calories, but does not uniquely contribute to excess calories or weight gain. Sugar, like other carbohydrates (starches), contains 16 calories per teaspoon, whereas fat contains 36 calories per teaspoon. Eating patterns high in fat are more likely to lead to excess calorie intake than those high in carbohydrate (sugars, starches, fibre). Because no single factor causes weight gain, decreasing or avoiding specific foods or nutrients in isolation will not prevent weight gain, or lead to weight loss. Rather than eliminate specific foods, it's better to match the amount of energy consumed from food with the amount of energy expended, which can be increased by physical activity.

Does the sweet taste of sugar encourage people to over-eat?

No. Although our appetite for sweet taste is with us from birth, sugar and other carbohydrate sweeteners do not encourage people to overindulge. In fact, our preference for sweet flavours is actually reduced as we experience fullness after eating.

What is the best way to lose weight?

To lose weight, fewer calories must be consumed than used by the body, so a modest decrease in caloric intake and increase in physical activity is advisable. Carbohydrates (starches and sugars) should make up the majority of calories, just as recommended for healthy eating. The rest of the calories will come from fat and protein. Weight loss should be slow and steady (0.5-1 kg or 1-2 lbs per week), not rapid.

To learn more about sugars and weight management, see our resources Clips on Sugars - Balancing Food and Activity for Healthy Weights, and Clips on Sugars - Calories and Body Weight.