Carbohydrates in Dog and Cat Food PDF - PFMA

FACT SHEET Carbohydrates in Dog and Cat Food People often use the terms ‘Carbohydrates’ or ‘Carbs’ when they are probably referring to starches! This is not a correct use of the term because starches are only one type of carbohydrates. Sugars, starches and dietary fibres (including prebiotics) are...

FACT SHEET Carbohydrates in Dog and Cat Food People often use the terms ‘Carbohydrates’ or ‘Carbs’ when they are probably referring to starches! This is not a correct use of the term because starches are only one type of carbohydrates. Sugars, starches and dietary fibres (including prebiotics) are all different types of carbohydrates with different roles in the body of animals. Carbohydrates are one of the three categories of macro-nutrients (along with proteins and fats) in the diet of animals. Carbohydrates are important because they are the main source of energy as well as components of other molecules like DNA. The image below shows what carbohydrates category includes and how small or big the molecules are. Basic classification and illustration of carbohydrates C CARBOHYDRATES ARBOHYDRA HYDRAT ATES SIMPLE COMPLEX POLY CCHARIDES LYSA POLYSACCHARIDES SUGARS SUGARS STARCHES STA ARCHES DIETRY FIBRE MONOSACCHARIDES MONOSACCHARIDES DISACCHARIDES DISACCHARIDES SOLUBLE SOLUBLE INSOLUBLE INSOLUBLE (e.g. glucose) glucose) (e.g. sucrose) sucrose) (e.g. pectin) cellulose) (e.g. cellulose) Structure of carbohydrates Can dogs digest cooked starch? Carbohydrates are molecules made from just three elements: Despite the perception held by some that dogs should eat the carbon, hydrogen and oxygen. The smallest and simplest form of same food as wolves, studies have shown they can digest cooked carbohydrates are sugars which are also called Monosaccharides starch. A genome study of dogs and wolves, published in Nature (e.g. glucose) and disaccharides (e.g. sucrose). Other carbohydrate journal in 2013 showed that dogs have genes enabling them to molecules are much larger and include polysaccharides such as digest cooked starch2. The study looked into genomes of 14 starch and dietary fibre. different breeds of dogs and compared them to genomes of wolves and indicated that dogs have the ability to digest starches Sugars and break them down into sugars as available source of energy. This evolutionary change has occurred in the past 10,000 years of Monosaccharides humans farming crops and domesticating dogs, resulting in both Glucose is the most important fuel (source of energy) in animal humans3 and dogs being able to eat starch. cells but it is rarely available in nature. When enzymes break down the larger macro-nutrients in the body, glucose becomes How about cats? available. Its small size and character allows it to pass through the cell membrane and release energy when metabolised. Other While cats don’t have an examples of monosaccharides include fructose (also known as Did you know? absolute requirement for In the wild, both cats and fruit sugar) and galactose (a component of the disaccharide, starches, they are able to dogs would consume lactose, also known as milk sugar). utilize them as an energy some carbohydrates Disaccharides source. Manufacturers of from the digestive Most available sugars found in nature are disaccharides. They are cat food use those tract of their made of two monosaccharides that are joined together. Examples carbohydrates that are prey! are sucrose, lactose and maltose. If a cat or a dog has reduced levels easily and rapidly broken of the specific enzyme to break down disaccharides, they may show down in the digestive signs of sensitivity and intolerance towards food containing it1. tract of the cats. This includes the starchy Starches portion of plants such as rice, wheat, corn and barley which are easily digested by cats when As shown in the above illustration, long chains of monosaccharides cooked.4 It is however important to remember cats need a much can form polysaccharides (starch and fibre). Starch is often higher level of protein and fat to remain healthy, compared to dogs. produced in plant cells as a way of storing energy. Cats and dogs have the enzymes to break them down into smaller molecules, which can then produce energy for their cells. www.pfma.org.uk  FACT SHEET Carbohydrates in Dog and Cat Food Dietary Fibre Sources of Carbohydrates Dietary fibre is a general term for the edible parts of plants that are It is important to note that most plant based foods will have a resistant to digestion. Like the human, cats and dogs lack enzymes combination of different carbohydrates (sugar, starch and dietary to break down dietary fibre5. Dietary fibre has many health benefits fibre) in different amounts. For example: for dogs and cats. There are different classifications of dietary fibre6, Wheat Oats dried peas unmolassed sugar one of which is based on their solubility in water: beet pulp moisture % 15 14 14 10 Soluble fibre, which dissolves in water and is fermented in the starch % 60 38 44 4 colon has many benefits for cats and dogs. It keeps the digestive sugars % 2.5 1.5 4 8 tract healthy by stimulating beneficial bacteria and increased soluble dietary fibre % 0.5 2.9 1 19 viscosity. Soluble fibre can be found in different quantities in insoluble dietary fibre % 6 28 17 40 cereals, fruits and vegetables. Insoluble fibre, which does not dissolve in water, can be Labelling of carbohydrates in pet food metabolically inert, but may also contain some prebiotic fibre which ferments in the large intestine. Insoluble fibre absorbs According to the EU law, it is mandatory to declare quantity of water as it moves through the digestive system, providing bulking certain nutrients on all pet food labels, but that depends on the and easing defecation and improving faecal consistency. Insoluble species of animal. For cats and dogs the following nutrients must fibre is not a source of energy for cats and dogs and therefore will be declared under Analytical Constituents: not contribute to weight gain. That’s why it is used in specially formulated ‘light’ diets to provide satiety without contributing Protein (or Crude Protein) energy. Insoluble fibre can be found in high concentration in Crude fibres whole grains and fruit skin. Fat content (or Crude oils and fats) Crude ash (or Incinerated residue or Inorganic matter) For other pet food and nutrition topics Crude fibre is a measure that is determined by laboratory please see www.pfma.org.uk/fact-sheets testing and needs to be on the label. However, it is not an indication of carbohydrate content of the product. 1 Wills, J., and R. Harvey. “Diagnosis and management of food allergy and Although labelling of sugars and starches separately is not intolerance in dogs and cats.” Australian veterinary journal 71.10 (1994): mandatory, a simple formula will allow you to work out their total: 322-326. 2 Axelsson, Erik, et al. “The genomic signature of dog domestication reveals adaptation to a starch-rich diet.” Nature 495.7441 (2013): 360- % Carbohydrate = 100 – (% protein + % fat + % moisture + % ash) 364. 3 Perry, George H., et al. “Diet and the evolution of human amylase gene In this formula, If % moisture is not listed on the label, assume it is copy number variation.” Nature genetics 39.10 (2007): 1256-1260. 4 De-Oliveira, L. D., et al. “Effects of six carbohydrate sources on diet 10% digestibility and postprandial glucose and insulin responses in cats.” Journal of animal science 86.9 (2008): 2237-2246. 5 Please note some dietary fibre (whether soluble or insoluble) may be fermentable in the digestive tract and release small amounts of energy 6 For more information on classification of dietary fibre please visit our website www.pfma.org.uk/carbohydrate-factsheet www.pfma.org.uk