In most kitchens, bread goes straight from the shop to the bread
bin, maybe the fridge at a push. Now a viral freezer hack is
quietly rewriting that routine.
Stashing your loaf in the freezer before toasting it is being
sold online as a gut-friendly, weight-loss trick, yet there is real
science behind the health benefits of freezing bread. The twist
lies in how cold changes its starch.
What freezing bread in the freezer does to its starch
Starch in bread is made of amylose and amylopectin, which swell
and soften when the dough bakes. ‘During retrogradation, some of
the starch molecules realign and form new crystalline structures
that are more difficult for the body to digest and absorb, hence
their name, ‘resistant starch,” registered dietitian Avery Zenker
told HuffPost.
Fresh white bread contains only a small
amount of this resistant starch. ‘Fresh-baked white bread contains
about 0.5 to 1.7% resistant starch by weight. After cooling or
freezing and thawing, this might increase to 1 to 3%’, Zenker
said.
Cooling is the key, but where you store your loaf matters for
taste. ‘For refrigeration, the texture ends up being drier as the
cooler temperature and circulation of the fridge dehydrates the
product unless tightly sealed when cooled’, said Brian Chau,
principal food scientist at Chau Time, speaking to HuffPost.
Freezing slows staling and keeps flavour for longer, while still
nudging starch into a more rigid form. ‘When thawing frozen foods,
the cell structures rupture from the ice formation’, Chau said.
‘This can further rearrange the starch alignment to create a
different and possibly more resistant structure of starches in the
food.’
Those structural tweaks show up in blood tests. A small 2008
trial in the journal European Journal of Clinical
Nutrition found that white bread that had been frozen and
thawed, then eaten plain or toasted, led to significantly lower
glycaemic responses, by up to 39%, than fresh homemade bread.
Why frozen bread can be kinder to blood sugar and your gut
‘Resistant starch slows the absorption of other carbohydrates
into the blood’, Zenker explained. ‘Because less of the
carbohydrates in the food are absorbed, the impact on blood sugar
is more blunted, reducing blood glucose and insulin spikes. This
supports steady energy throughout the day, helps prevent sugar
crashes and promotes feelings of fullness.’
Internal medicine specialist Dr Tania Elliott said freezing your
bread not only keeps your energy ‘steady’, but helps to ‘avoid big
sugar spikes and crashes’, calling the trick ‘better for your body,
especially if you are trying to lose weight’, in comments shared on
TikTok and reported by The Independent.
In the gut, that starch behaves like a prebiotic. ‘[Gut
bacteria] consume resistant starch and release beneficial compounds
called short-chain fatty acids (SCFAs) like butyrate’, Zenker said,
highlighting their role in fuelling colon cells and supporting the
gut barrier.
There may even be a small effect on appetite hormones.
‘Indirectly, resistant starch may impact satiety and blood sugar by
increasing GLP-1 production in the gut’, Zenker explained, while
cautioning that ‘it’s important to note that the benefit of
resistant starch is small, so moderate portions still matter.’
How to freeze bread for gut health
without the hype
To get the most from the freezer trick, dietitians suggest a
simple routine:
- Slice the loaf and pack it tightly in a freezer bag.
- Freeze for at least overnight before eating.
- Toast straight from frozen or after a quick thaw.
Freezing does not remove carbs or gluten, it just changes how
quickly they hit the bloodstream, and similar cooling tricks apply
to cooked rice, pasta and potatoes.