I read an article in The Times supplement last weekend that throws some conventional ideas about diet and fitness on their head!
The article was a promotion for a new book written by practising doctor and nutrition expert Dr John Briffa and included extracts from the book ‘Escape the diet trap’.
Basically he’s saying that conventional views on calorie counting, low fat foods, high carb intakes and aerobic exercise are bad for you if you want to lose weight and don’t work. Here are his reasons why:
· Restricting calories leads to lowered metabolic rate – causing weight loss to stall at a higher level than ideal.
· Restricting calories also leads to increased cortisol levels which pre-dispose to fat accumulation around the middle of the waist and can lead to insulin resistance.
· Research shows that diets that are richer in fat and more restricted in carbohydrate than traditionally advised are better for weight loss and better at improving markers for type 2 diabetes and cardiovascular disease.
· Low-fat diets have been proved to be ineffective for weight loss. Briffa explains that fat storage is not simply about calories but is under hormonal control, namely insulin. Insulin helps deposit fat into cells and keeps it there and eating a carbohydrate rich diet increases insulin levels – promoting the storage of fat. Paradoxically, diets rich in fat and relatively low in carbs actually lower insulin levels, allowing the body to give up its fat stores more easily.
· Eating less saturated fat has not been associated with reduced heart disease but avoiding industrially produced, partially hydrogenated ones is.
· Prolonged aerobic exercise such as running, rowing and cycling is associated with good health but not with weight loss. They do not burn calories quickly enough and make you hungry.
So what does John Briffa think we should be eating instead and what should we avoid?
· Eat a diet relatively rich in protein – protein satiates appetite and reduces hunger. Eat only fresh, unprocessed meat, fish (especially oily fish), seafood and eggs.
· Eat only ‘natural’ fats, including saturated animal fats, olive oil, butter, avocado oil, coconut oil and full-fat yogurt.
· Reduce carbohydrate intake, particularly those that contain added sugar and/or starch.
· Avoid all processed and manufactured foods including soya based products and breakfast cereals. Also avoid beans, lentils and peas which are rich in potentially toxic substances called lectins.
· Drink plenty of fluids. There is evidence that dehydration inhibits the uptake of glucose into cells, leaving blood sugar levels high and hindering the mobilisation of fats from cells.
What about exercise?
(Remember, this is to promote weight loss rather than get super fit)
Briffa suggests the best exercise to promote weight loss is High Intensity Intermittent exercise (HIIE). This is brief, intense exercise with periods of relative rest. Research has shown that there is improved insulin sensitivity, which would be expected to speed weight loss. HIIE also was found to stimulate the metabolism of fat and fat loss.
Example of an HIIE routine using either a cycling, running or rowing machine:
· 2 minute gentle warm up on the machine
· 10 second ‘sprint’ on machine at about 80-90% maximum intensity
· Slow cycle, jog or row for 30 seconds
· Repeat cycle or 6-10 sprints
· 2 minute cool down on machine
There are some interesting ideas here. I like the scientific rationale being put forward; it generally fits in with my basic understanding of biochemistry and metabolism. I may even download the Kindle version of the book…..
What do you think?
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