Glycaemic index, glycaemic load and the Sweet flavour in TCM

Of all the convergences between modern science and traditional Chinese medicine, the one between the glycaemic index and the Sweet flavour is perhaps the most illuminating. What TCM describes as ‘nourishing the Spleen with a moderate Sweet flavour’ corresponds precisely to ‘maintaining a low glycaemic load to preserve insulin sensitivity’. And what it calls ‘harming the Spleen through excess Sweetness’ corresponds exactly to ‘provoking insulin resistance through repeated glycaemic spikes’.

The Sweet flavour in TCM: far more than a taste

The nourishing Earth

Within the Five Elements system (Wu Xing 五行), Earth occupies a unique position: it is the centre, the pivot around which the four other elements revolve. The Sweet flavour (Gan Wei 甘味), the flavour of Earth, is considered the fundamental flavour of nutrition - the only one that directly tonifies Qi and Blood, nourishes the tissues and harmonises the other flavours.

「

The five grains nourish, the five fruits assist, the five meats complete, the five vegetables fill. The flavours associated with the aroma of foods nourish Qi and Essences.

」

The three levels of the Sweet flavour

Light Sweet (Dan Gan 淡甘): the Sweet flavour of wholegrains, legumes and root vegetables. It nourishes Spleen Qi gently, without overloading it. Glycaemic index: low to moderate (30-55). This forms the recommended foundation of the daily diet.

Rich Sweet (Nong Gan 浓甘): the Sweet flavour of dense, nourishing foods - meats, eggs, honey, dates, dried fruits. It tonifies Qi and Blood at a deeper level. Variable glycaemic index. Recommended during convalescence, but to be used in moderation in those with pre-existing Spleen deficiency.

Excessive Sweet (Guo Gan 过甘): white sugar, syrups, confectionery, white flour, industrial fruit juices. This concentrated, refined form barely exists in nature. In TCM, it is pathogenic: it overloads the Spleen beyond its capacity, generates Dampness on a large scale, and over time produces Phlegm. Glycaemic index: high (70-100).

Glycaemic index and glycaemic load: measuring the real impact

Glycaemic index: the speed of sugar

The glycaemic index (GI), developed by David Jenkins in 1981, measures the rate at which a carbohydrate-containing food raises blood glucose over the two hours following ingestion, relative to pure glucose (GI = 100).

• High GI (70 and above): rapid, sharp rise. White bread (75), white rice (73), potato (78), cornflakes (81), table sugar (65).
• Moderate GI (56-69): intermediate rise. Basmati rice (58), ripe banana (62), sweet potato (63), wholemeal bread (65).
• Low GI (55 and below): slow, gradual rise. Lentils (32), chickpeas (28), apple (36), rolled oats (55), quinoa (53).

Glycaemic load: quantity also matters

GI alone does not account for the actual quantity consumed. Glycaemic load (GL) incorporates both:

GL = (GI x grams of carbohydrate per serving) / 100

Watermelon has a high GI (72) but a low GL per serving (4), because it contains relatively little carbohydrate. By contrast, a portion of white rice (GI 73, GL 29 for 150g cooked) combines both a high GI and a high GL - the most damaging combination for insulin.

The factors that modify GI

• Cooking: al dente pasta (GI 45) has a lower GI than overcooked pasta (GI 55). Rice that has been cooked, cooled and reheated has a lower GI due to the formation of resistant starch.
• Soluble fibre: it forms a viscous gel that slows glucose absorption. This is why wholegrain cereals have a lower GI than their refined counterparts.
• Protein and fat: adding these to a carbohydrate-containing meal significantly reduces the glycaemic response by slowing gastric emptying.
• Organic acids: apple cider vinegar, lemon juice and fermented foods reduce a meal’s GI by 20 to 30% (Ostman et al., 2005, European Journal of Clinical Nutrition).

Tables of low-GI foods compatible with TCM

Grains and pseudo-grains

Aliment	Nature	Saveur	Méridiens	Actions	Précautions
Buckwheat (Qiao Mai 荞麦)	Frais	Sweet	Spleen, Stomach, Large Intestine	GI 40 - draining, subdues Liver Yang	Profiles A and C - avoid with internal Cold
Millet (Xiao Mi 小米)	Tiède	Sweet, Salty	Spleen, Stomach, Kidney	GI 71 but low GL - tonifies Spleen and Kidney	Ideal for Profile B - the Spleen's royal grain
Barley (Da Mai 大麦)	Frais	Sweet, Salty	Spleen, Stomach	GI 28 - drains Dampness, strongly cooling	Ideal for Profile C - avoid with weak Yang
Rolled oats	Tiède	Sweet	Spleen, Stomach	GI 55 - beta-glucans improve insulin sensitivity	Profiles A and B
Wholegrain basmati rice	Neutre	Sweet	Spleen, Stomach	GI 50 - neutral, suitable for all profiles	Universal - a safe base for everyone
Quinoa	Neutre	Sweet	Spleen, Kidney	GI 53 - complete proteins and amino acids	Universal - profiles A, B and C

Legumes

Aliment	Nature	Saveur	Méridiens	Actions	Précautions
Green and red lentils	Neutre	Sweet	Spleen, Heart	GI 32 - GL 6 - best GI-to-satiety ratio	Universal - profiles A, B and C
Chickpeas (cooked)	Neutre	Sweet	Spleen, Stomach	GI 28 - GL 2 - rich in soluble fibre	Universal - ideal for profiles A and C
Adzuki beans (Chi Xiao Dou 赤小豆)	Neutre	Sweet, Sour	Spleen, Heart, Kidney	GI 35 - specifically drain Dampness	Profile B with Dampness and oedema
Mung beans (Lu Dou 绿豆)	Frais	Sweet	Stomach, Heart	GI 31 - draining, anti-inflammatory	Profile C - Dampness-Heat
Soya beans (cooked)	Neutre	Sweet	Spleen, Large Intestine, Kidney	GI 15 - very low - protein and fibre	Profiles A and C - moderate with hypothyroidism

Flavour balance: Sweet + Bitter + Pungent

The Sweet flavour never functions alone in Chinese dietetics. It is balanced with the four other flavours to create harmonious eating:

Sweet + Bitter = drain Dampness. The bitter flavour dries Dampness. Pair grains (Sweet) with bitter green vegetables (endive, rocket, dandelion, artichoke). In modern terms, bitter compounds stimulate bile secretion and improve lipid metabolism.

Sweet + Pungent = move Qi. The pungent flavour circulates Qi and warms. Systematically add spices (ginger, turmeric, pepper, cardamom) to dishes of grains and legumes. Pungent compounds (gingerol, curcumin, piperine) stimulate thermogenesis and improve insulin sensitivity.

Sweet + Sour = contain and aid digestion. A squeeze of lemon, a few berries or a fermented condiment (apple cider vinegar, sauerkraut, miso) slows gastric emptying and reduces a meal’s GI by 20 to 30%.

FAQ

Is it necessary to eliminate all carbohydrates to reduce insulin?

No. Eliminating all carbohydrates is an extreme approach that may be useful in the short term for Profile A (severe insulin resistance), but is contraindicated for Profile B (Yang deficiency), where warm wholegrains are indispensable. The objective is to replace high-GI carbohydrates with their low-GI equivalents and reduce overall glycaemic load - without total elimination.

Is sweet potato better than regular potato?

In GI terms, the difference is notable: cooked sweet potato (GI 63) versus cooked potato (GI 78-95, depending on preparation). More importantly, in TCM, sweet potato (Shu Yu 薯蓣) tonifies the Spleen and Kidney with a neutral to slightly warm nature, making it compatible with all profiles. Regular potato has no specific tropism in TCM, and its high GI makes it less advantageous.

Is wholemeal bread really low GI?

Not always. Wholemeal wheat bread has a GI of 65-70, almost as high as white bread. Sourdough wholemeal bread has a significantly lower GI (52-65), because the acidification through fermentation slows glucose absorption. The most advantageous breads are wholegrain rye bread (GI 41-50) and spelt sourdough bread (GI 54).

Back to the main guide: Metabolism and Weight Loss - Complete TCM and Science Guide