There are a number of disadvantages to the Pritikin diet:

• Extremely low in fat (only 10%) which may not be enough
• Very low fat intake may impair absorption of fat-soluble vitamins
• Diet is very low in omega-3 fatty acids (unless fish is consumed)
• High fibre intake can cause flatulence and bloating
• Diet may not satisfy and be palatable for all people
• May be difficult to maintain this diet over the long term
• A lot of time is required for proper food preparation

“Very low fat diets, such as the Pritikin Principle diet could impair absorption of some of the fat-soluble vitamins (A, D, E, K)”

REFERENCES

1. The recommended intake of fat on a daily basis is around 30-35%, which is a lot higher than the intake in the Pritikin diet. The low fat intake may make it difficult to absorb the fat-soluble vitamins such as Vitamin A, D, E and K – these vitamins require fat to be absorbed into the body. This means a deficiency of these vitamins may occur
2. The low intake of fats and especially if there is no intake of fish, may cause a deficiency of omega-3 fatty acids. The Pritikin diet recommends regular intake of fatty deep ocean fish, such as salmon, trout and mackerel and vegetarians/vegans can get their omega-3 fatty acids intake from nuts and other plant foods or supplements, but people need to be aware that this vital nutrient is necessary for many of the body’s processes to function correctly and should ensure they eat enough foods high in omega-3 fatty acids
3. Bianchi M, Capurso L. Effects of guar gum, ispaghula and microcrystalline cellulose on abdominal symptoms, gastric emptying, orocaecal transit time and gas production in healthy volunteers. Dig Liver Dis. 2002 Sep;34 Suppl 2:S129-33. Accessed on 17 January 2008. This study on healthy individuals showed that some types of fibre causes abdominal bloating and flatulence (gas)
4. The high intake of fruits, vegetables and grain with little meat-based protein and very low fat may not suit all people, some of whom may find it difficult to stay on this diet for any substantial length of time and even for people who do enjoy the diet, it still may be difficult to sustain the diet forever
5. Due to the recommendation of having a high intake of natural, unprocessed foods, there is very little opportunity to buy any packaged foods, which means all food must be prepared each day, which takes up a lot of time, which many people do not have and this is also a reason why the diet is often abandoned after some time