For weight loss, patients often ask how many calories they should eat and what percentage of those calories should be composed of fat, protein and carbohydrate. That depends on a number of factors: type and level of physical activity, gender, age, body composition, how much weight you want or need to lose and overall metabolism. So the answer is very individual. Apps like My Fitness Pal, can help to take all these factors into account to give an estimation of your daily calorie requirements and help track caloric intake and energy expenditure. Regardless, to lose a pound, one needs to burn 3500 kcal more than you take in.
Calories are units of energy that we obtain from food and that our bodies can burn for fuel. Taking in too much fuel without burning an equivalent amount off, means that the excess fuel gets stored as fat. So at the most basic level, you need to burn more calories than you take in.
A person is a person no matter how small (Dr Seuss), but a calorie isn’t a calorie no matter where it’s from! How your body handles calories varies, depending on the source of the calories. To store extra calories as fat, the body has to use some energy. The amount of energy required to store excess dietary carbohydrate as fat is only 6% to 8% of the calories being stored, and for protein is about four times that at 25% to 30%1. So even if you are taking in extra calories, if those calories come from protein fewer of them will be stored than if those excess calories come from starches and sugars.
What about calories from fat, aren’t they bad?
Calories from fat aren’t any worse than any other calories, although many fatty foods are very unhealthy (French fries, pizza, burgers etc.) and contain particularly bad combinations of high saturated fat and processed, high glycemic index carbs. Healthy fats can help you to feel full and slow down your digestion. Studies have shown that reducing one’s fat intake leads to an increase in total caloric intake, which is exactly what we don’t want2. Another study found that a Mediterranean diet supplemented with either olive oil or walnuts, actually helped to reverse Metabolic Syndrome (a condition associated with high blood pressure, high cholesterol/triglycerides, insulin resistance and greater risk of heart disease)3. Reversing insulin resistance is one of the best ways to help with weight loss.
Aside from taking extra effort to store calories from dietary protein as fat, protein supplies our bodies with amino acids, the building blocks for us to make our own proteins.
So What is the Right Proportion of Calories from Protein, Fat and Carbohydrate?
Good question and there doesn’t seem to be a definitive answer, some research seems to suggest that it doesn’t really matter so long as the calories stay low. Total caloric intake is important, especially in the context of how much energy you tend to burn in a day. If foods high in fibre, fat and protein help people feel full sooner and consume fewer calories, then it may be important to emphasize calories from lean protein, healthy fats and high fiber vegetables like broccoli, while minimizing calories from high glycemic index carbohydrates (starches and sugars) which leave people hungry afterward.
How can protein help with weight loss?
Dietary protein helps people feel full, stabilizes blood sugar and helps preserve lean body mass4. Who doesn’t want more lean body mass?
Emotional Eater? You may want to stock up on the amino acids tyrosine and l-tryptophan. These are used in the body to make brain chemicals called neurotransmitters that calm down the nervous system (GABA, dopamine and norepinephrine) and help us feel happy (serotonin). Good food sources for tyrosine include: chicken, turkey, almonds, avocados, lima beans, pumpkin seeds and sesame seeds. You can get l-tryptophan from chicken, turkey, shrimp, halibut, herring, sardines, pumpkin seeds, black beans and split peas.
Want to Increase Muscle Mass?
Muscle burns more calories than fat, even while you are sleeping. To build more muscle you need a combination of two things: resistance exercise (weight training) and higher blood amino acid levels after eating5. This is the perfect recipe for muscle building. Dietary proteins that contain all of the essential amino acids are important. Essential amino acids are those that humans need, but we are unable to make, therefore we have to acquire them through food. They are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine. The best protein rich foods include lean meat, fish, and poultry, and eggs. Amino acids, such as leucine, have also been shown to help protect metabolically active tissues like muscles during weight loss and increase loss of body fat6.
Based on all of the above factors, a diet higher in lean protein, healthy fats, low whole, high fiber starches and minimal or no sugar is optimal for body composition, mood and weight loss.
Pamela Frank, BSc(Hons), ND has been in practice as an ND since 1999 and previously worked for 20 years as a medical laboratory technologist. She is Clinic Director of Forces of Nature Wellness in Toronto and was twice voted “Best Naturopath in Toronto”. Pamela maintains a busy, diverse practice with particular expertise in naturopathic treatment of PCOS, PMS, menopause, acne, infertility, uterine fibroids and endometriosis. Pamela’s interests include fitness, triathlons, yoga, healthy cooking, tennis and volleyball.
- Colin Wilborn, Jacqueline Beckham, Bill Campbell, Travis Harvey, Melyn Galbreath, Paul La Bounty, Erika Nassar, Jennifer Wismann and Richard Kreide. Obesity: Prevalence, Theories, Medical Consequences, Management, and Research Directions. Journal of the International Society of Sports Nutrition 2005, 2:4-31
- Walker TB, Parker MJ. Lessons from the war on dietary fat. J Am Coll Nutr. 2014;33(4):347-51.
- Babio N, Toledo E, Estruch R, Ros E, Martínez-González MA, Castañer O, Bulló M, Corella D, Arós F, Gómez-Gracia E, Ruiz-Gutiérrez V, Fiol M,Lapetra J, Lamuela-Raventos RM, Serra-Majem L, Pintó X, Basora J, Sorlí JV, Salas-Salvadó J; PREDIMED Study Investigators. Mediterranean diets and metabolic syndrome status in the PREDIMED randomized trial. CMAJ. 2014 Nov 18;186(17):E649-57.
- Campbell AP, Rains TM. Dietary protein is important in the practical management of prediabetes and type 2 diabetes. J Nutr. 2015 Jan;145(1):164S-169S.
- Phillips SM. A brief review of critical processes in exercise-induced muscular hypertrophy. Sports Med. 2014 May;44 Suppl 1:S71-7.
- Devkota S, Layman DK. Protein metabolic roles in treatment of obesity. Curr Opin Clin Nutr Metab Care. 2010 Jul;13(4):403-7.