Why is diet and specifically protein so important?
Protein Intake and Healthy Nutrition During Medical Weight Loss
Why Protein Matters During Weight Loss
When losing weight, the goal is not simply to see a lower number on the scale—it is to lose excess body fat while preserving muscle mass. Adequate protein intake is one of the most important factors in maintaining muscle during weight loss.
This becomes especially important when using medications such as semaglutide (Wegovy®, Ozempic®) or tirzepatide (Zepbound®, Mounjaro®), as appetite suppression often leads people to eat significantly less overall. While reducing calories can help promote weight loss, consuming too little protein may increase the risk of muscle loss, weakness, fatigue, and a slower metabolism.
Protein also helps:
Increase feelings of fullness and satiety
Reduce hunger and cravings
Support muscle maintenance and repair
Improve strength and physical function
Support bone health
Help maintain metabolic rate during weight loss
How Much Protein Do You Need?
The recommended dietary allowance (RDA) for protein in healthy adults is 0.8 grams per kilogram of body weight per day, but this is considered the minimum amount needed to prevent deficiency—not necessarily the amount needed to optimize health during weight loss.
For individuals actively trying to lose weight, experts generally recommend a higher protein intake.
A reasonable target for many adults is:
1.2–1.6 grams of protein per kilogram of ideal body weight per day
Some individuals who are very physically active, older adults, or those participating in regular resistance training may benefit from:
1.6–2.2 grams of protein per kilogram per day
What Does That Look Like?
Examples:
70 kg (154 lb) individual:
85–110 grams protein/day
80 kg (176 lb) individual:
95–130 grams protein/day
90 kg (198 lb) individual:
110–145 grams protein/day
Rather than consuming most of your protein at one meal, it is generally beneficial to spread protein intake throughout the day.
A simple goal is:
20–40 grams of protein per meal
Healthy Sources of Protein
Animal-based:
Fish and seafood
Chicken and turkey
Lean beef and pork
Eggs
Greek yogurt
Cottage cheese
Milk
Plant-based:
Tofu and tempeh
Edamame
Lentils and beans
Chickpeas
Soy milk
Nuts and seeds
Protein-fortified foods
Protein powders can also be useful for some individuals who struggle to meet their protein goals through food alone.
Building a Healthy Plate
While there is no single "perfect" diet, most evidence-based nutrition recommendations share common principles.
A simple approach is:
Half Your Plate
Vegetables and fruit
Focus on a variety of colourful vegetables and fruits to provide:
Fibre
Vitamins and minerals
Antioxidants
Improved fullness with fewer calories
One Quarter of Your Plate
Lean protein
Examples:
Fish
Poultry
Eggs
Tofu
Greek yogurt
Legumes
One Quarter of Your Plate
High-fibre carbohydrates
Examples:
Whole grains
Brown rice
Quinoa
Oats
Sweet potatoes
Beans and lentils
The Importance of Fibre
Many Canadians do not consume enough fibre.
Fibre can:
Improve fullness
Support gut health
Improve cholesterol levels
Help regulate blood sugar
Support regular bowel movements
Most adults should aim for approximately:
Women: 25 grams/day
Men: 38 grams/day
Good sources include:
Vegetables
Fruit
Legumes
Whole grains
Nuts and seeds
Healthy Fats Are Important Too
Healthy fats support:
Hormone production
Brain health
Heart health
Absorption of certain vitamins
Sources include:
Olive oil
Avocados
Nuts
Seeds
Fatty fish such as salmon and trout
Diets to Be Cautious About
Many popular diets promise rapid weight loss but can be difficult to sustain long term.
Be cautious of approaches that:
Eliminate entire food groups without medical reason
Promote detoxes or cleanses
Rely heavily on supplements
Promise rapid or dramatic results
Provide fewer than 1,200 calories per day without medical supervision
The best nutrition plan is one that is:
Evidence-based
Nutritionally balanced
Enjoyable
Sustainable long term
Adaptable to your lifestyle and preferences
Progress Over Perfection
Healthy weight management is not about being perfect. Small, consistent habits practiced over time often lead to the most successful and sustainable results.
Combining adequate protein intake, resistance training, regular physical activity, quality sleep, stress management, and evidence-based medical therapies when appropriate can help support long-term success while preserving muscle mass and improving overall health.
