DIET AND DIABETES by liwenting


1. Appreciate the association between dietary fat and carbohydrate intake and the regulation of blood glucose

Blood glucose needs to be tightly regulated as the brain requires a constant supply of glucose and can only get it from the
blood supply. BGL are normally maintained within narrow limits (4-8mmol/L)
 If BGL <2-3mmol  coma and even death
 If BGL >10mmol  excess glucose excreted in urine (polyuria, polydipsia)

Normal blood glucose homeostasis largely depends on the state of the patient (fed or fasted).
 Fed (INSULIN >glucagon) – Removes glucose from the blood and stores it (glycogenolysis and lipogenesis)
 Fasted (GLUCAGON > insulin) – Releases glucose from stores and produces new glucose (glycogenolysis,

The liver plays a central role in “intermediary metabolism”. Portal blood from the intestines carries CHO and AA (Fats
carried via lymph) straight to the liver where:
 Glycogen and TAG are made (storage) - FED
In the fasted state, glucagon is released:
 Liver degrades glycogen and then carries out gluconeogenesis to release glucose into the blood

 Type 1 diabetes (no insulin production) – no insulin = hyperglycaemia (can’t store excess glucose AND glucagon is
    unopposed, triggering glycogenolysis and gluconeogenesis) and lipogenesis  ketone production  ketoacidosis
    as well
 Type 2 diabetes (insulin resistance) – cells don’t respond to insulin = hyperglycaemia

2. Be able to give patients with Type II diabetes advice on nutritional and life style modifications that may help in
the management of their disease

The diet for diabetes is the same as the diet that is considered healthy for everyone. Basically, food for diabetics should
 Low in sugar (though not sugar free)
 High in starchy carbohydrate (especially foods with a low GI)
 High in fibre
 Low in fat (especially saturated fat)

Most people find changing their eating habits very difficult, so it is important to repeat your advice and encourage them. It
is a good idea to take a diet history and prescribe a diet that involves the least possible interference with their lifestyle.
Advice from dieticians is more likely to affect medium-term outcomes than from a doctor, so referring them to a dietician is
a good idea.

Those taking insulin or oral therapy should be encouraged to eat roughly the same amount of food (esp. carbs) at roughly
the same time every day so that treatment can be balanced against intake and exercise.

Recommended composition of the diet for people with diabetes (From Kumar & Clark and Diabetes Australia
Food Fact sheet)
 Component of         Recommended amount                                 How this may be achieved
     the diet
Protein              1g/kg ideal body weight      Eat lean meat, eggs (not fried), nuts, tofu

Total fat            <35% of energy intake        Limit fat/oil in cooking (try dry-roasting, poaching etc)
                                                  Limit fried foods, processed meals, high-fat snacks, creamy sauces etc
                                                  Encourage lower-fat dairy, lean meat

Saturated fat        <10% of daily intake         Eat fish (esp. oily fish) once/twice weekly. Stir-fry meals in a little
                                                  canola oil, use linseed bread, snack on nuts (small amount)

Monounsaturated      10-20% of daily intake       Cook with olive oil (not butter), avocado
Total                40-60% of energy intake      Limit sweet drinks/juices, confectionary, cakes, biscuits etc
carbohydrate         (spread intake evenly        Encourage using artificially sweeteners instead of sugar
                     through the day)             Low GI foods – grainy bread, basmati rice, pasta, grains, legumes,
                                                  fruit, starchy vegetables (sweet potato, corn)

                     >10% of daily intake         Eat in the context of a healthy diet (e.g. fibre-rich cereals, baked beans)
                     No absolute quantity         Eat plenty of fruits/vegetables and high-fibre cereals etc.
Fibre                recommended
Vitamins             Best taken as 5 portions     Best taken in as fruit/vegetables
                     of fruit/vegies per day
Alcohol              Limited                      Use with caution – energy content is very high and it has the tendency
                                                  to cause delayed hypoglycaemia in those on insulin. Avoid sweet
                                                  mixers (water/diet drinks instead). Opt for light beer.
                                                  Have at least 2 alcohol free nights per week
Salt                 <6g/day                      Don’t add salt to foods, avoid processed foods/meats etc, choose low-
                                                  salt alternatives

Physical activity
Emphasise the positive effect that physical activity can have on their glycaemic control and thus reduce morbidity and
 Ideally, they need moderate exercise 20-30 minutes most days of the week. Tips:
         o Walk instead of using public transport
         o Garden regularly
         o Get a dog – encourages walking
         o Park the car further from destination

Other lifestyle modifications
 Quit smoking
 Limit alcohol

Yearly checks:
 Biochemical assessment of metabolic control (glycoslyated Hb test)
 Weight
 BP
 Plasma lipids
 Visual acuity
 Retinal exam
 Urine test (proteinuria/microalbuminuria)
 Blood for renal function (creatinine)
 Check feet – condition, pulses, neuropathy
 Review CV risk factors
 Review eating habits, physical activity and self-monitoring techniques
 Continued education

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