Weight Management

Weight Management

Protein

Dietary protein can play an important role in successful and sustainable weight loss.

Since lean body mass burns more calories than fat tissue, preserving lean body mass during weight loss may help to prevent weight regain.1-5 Research has shown that increasing dietary protein levels can help overweight pets lose significantly more weight as fat and less as lean body mass.1-4,6

Protein

Purina's research

Cat and dog

Purina’s research with overweight dogs and cats showed that a high-protein diet helps protect lean body mass during weight loss.1,2

In one study, overweight dogs were fed low-calorie diets that contained 20%, 30% or 39% protein (on a metabolizable energy basis). Dogs were fed to achieve a loss of 1% body weight per week until each dog reached an ideal body condition score (a score of 5 using the 9-point Purina BCS system).1 ​

The overweight dogs fed the 30% or 39% protein diets lost approximately half as much lean body mass and more fat mass compared to dogs fed the 20% protein diet.1

Protein reduces loss of LBM and increases fat loss in dogs. This chart shows percentage of loss (body fat and Lean body mass) vs % of dietary protien in diet. 20% dietary protein showed a loss of 3350g of body fat and 1700g of LBM. 30% dietary protein showed a loss of 3420g of body fat and 900g of LBM. 39% dietary protein showed a loss of 3800g of body fat and 700g of LBM.
Obese cats fed 35% protein had weight loss composed of 79% fat and 20% lean tissue. Cats fed 45% protein had 88% fat loss and only 11% lean tissue loss.

In another study, obese cats were energy-restricted to achieve a loss of 1% body weight per week. They were fed dry diets that differed in the amount of protein (35% versus 45% of metabolizable energy).2​

Cats lost comparable amounts of total weight. However, compared with cats fed the 35% protein diet, cats fed the 45% protein diet lost significantly more weight as fat and less as lean body mass.2 ​

A second study with obese cats also found that those fed a high-protein diet lost more fat mass than those fed a low-protein diet.6

Additional benefits of high-protein diets may include:

  • Improved satiety in overweight and obese dogs due to a mitigation of leptin resistance.7
  • Reduced oxidative stress, which is important since obesity leads to an increase in oxidative stress.8
  • Mitigation of the decrease in energy expenditure that occurs after weight loss, potentially due to the higher thermogenic effect of protein compared to carbohydrate and fat.4,9,10

It’s not just the amount of dietary protein that contributes to a healthy body weight, Purina studies show that the ratio of dietary protein to carbohydrate can influence the gut microbiome and impact metabolism in both dogs and cats.11-13

Purina's research

Burmese cat

Feeding a high-protein, low-carbohydrate diet (HPLC) had more significant impacts on the composition of gut microbiota in overweight animals than in lean animals.11-13

For example, overweight cats (greater than 25% body fat) fed HPLC diets showed significant shifts in populations of gut bacteria that produce short-chain fatty acids (SCFAs).13

One of these bacteria, Megasphaera, may increase energy absorption by fermenting excess carbohydrates into SCFAs. ​

In this study overweight cats fed an HPLC diet had decreased Megasphaera, a change which potentially could contribute to weight loss.13

Shifts in gut bacteria when overweight cats were fed an HPLC diet:

Bacteria Decreased Increased
Phylum Fusobacteria increased by > 8 times
Family Veillonellaceae, Bifidobacteriaceae, Porphyromonadaceae, and Rikenellaceae Fusobacteriaceae, Clostridiaceae, Lachnospiraceae, Ruminococcaceae, Mogibacteriaceae, and Peptococcaceae
Genera Megasphaera, Veillonella, and Bifidobacterium Faecalibacterium and Fusobacterium
Species E. cylindroides, L. ruminis, and B. plebeius F. prausnitzii, R. gnavus, C. hiranonis, and E. dolichum

Key things to remember

  • An increased dietary protein-to-calorie ratio can help overweight dogs and cats lose significantly more weight as fat and less as lean body mass.
  • High-protein diets have also been shown to reduce oxidative stress and may improve satiety.
  • By influencing the gut microbiome, high dietary protein-to-carbohydrate ratios may positively affect metabolism in both dogs and cats.

Explore areas of managing a healthy weight

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  1. Hannah, S. S., & Laflamme, D. P. (1998). Increased dietary protein spares lean body mass during weight loss in dogs. Journal of Veterinary Internal Medicine, 12, 224. 
  2. Laflamme, D. P., & Hannah, S. S. (2005). Increased dietary protein promotes fat loss and reduces loss of lean body mass during weight loss in cats. International Journal of Applied Research in Veterinary Medicine, 3(2), 62–68. 
  3. des Courtis, X., Wei, A., Kass, P. H., Fascetti, A. J., Graham, J. L., Havel, P. J., & Ramsey, J. J. (2015). Influence of dietary protein level on body composition and energy expenditure in calorically restricted overweight cats. Journal of Animal Physiology and Animal Nutrition, 99(3), 474–482. 
  4. Vasconcellos, R. S., Borges, N. C., Gonçalves, K. N., Canola, J. C., de Paula, F. J., Malheiros, E. B., Brunetto, M. A., & Carciofi, A. C. (2009). Protein intake during weight loss influences the energy required for weight loss and maintenance in cats. The Journal of Nutrition, 139(5), 855–860. 
  5. German, A. J., Holden, S. L., Mather, N. J., Morris, P. J., & Biourge, V. (2011). Low-maintenance energy requirements of obese dogs after weight loss. British Journal of Nutrition, 106, S93–S96. doi: 10.1017/S0007114511000584 
  6. Hoenig, M., Thomaseth, K., Waldron, M., & Ferguson, D. C. (2007). Insulin sensitivity, fat distribution, and adipocytokine response to different diets in lean and obese cats before and after weight loss. American Journal of Physiology-Regulatory, Integrative, and Comparative Physiology, 292, R227–R234. 
  7. Blees, N. R., Wolfswinkel, J., Kooistra, H. S., & Corbee, R. J. (2020). Influence of macronutrient composition of commercial diets on circulating leptin and adiponectin concentrations in overweight dogs. Journal of Animal Physiology and Animal Nutrition, 104(2), 698–706. 
  8. Tanner, A. E., Martin, J., Thatcher, C. D., & Saker, K. E. (2006). Nutritional amelioration of oxidative stress induced by obesity and acute weight loss. Compendium on Continuing Education for the Practicing Veterinarian, 28(Suppl 4), 72. 
  9. Halton, T. L., & Hu, F. B. (2004). The effects of high protein diets on thermogenesis, satiety and weight loss: A critical review. Journal of the American College of Nutrition, 23(5), 373–385. 
  10. Astrup, A., Raben, A., & Geiker, N. (2015). The role of higher protein diets in weight control and obesity-related comorbidities. International Journal of Obesity, 39, 721–726. 
  11. Li, Q., Lauber, C. L., Czarnecki-Maulden, G., Pan, Y., & Hannah, S. S. (2017). Effects of the dietary protein and carbohydrate ratio on gut microbiomes in dogs of different body conditions. MBio 8, e1703–e1716. 
  12. Coelho, L. P., Kultima, J. R., Costea, P. I., Fournier, C., Pan, Y., Czarnecki-Maulden, G., Hayward, M. R., Forslund, S. K., Schmidt, T. S. B., Descombes, P., Jackson, J. R., Li, Q., & Bork, P. (2018). Similarity of the dog and human gut microbiomes in gene content and response to diet. Microbiome, 6, 72. doi: 10.1186/s40168-018-0450-3 
  13. Li, Q., & Pan, Y. (2020). Differential responses to dietary protein and carbohydrate ratio on gut microbiome in obese vs. lean cats. Frontiers in Microbiology, 11, 591462. doi: 10.3389/fmicb.2020.591462